Stinging Nettles under the Microscope

[00:00:58]Well, I do hope that you can hear me now.

[00:01:01]Yeah, I just realized uh that basically um there was no sound. I can at least hear myself and I'm quite sure that you can as well. Wrong microphone setting, but at least I got that sorted. Okay, so I'm going to start again. Hi. Hello everyone. and I'm Oliver and welcome to another microscopy live stream. Okay. Um yeah uh I'm back again. Last week uh um I a little bit unexpectedly well actually um I prepared to prepare I had to prepare a a video. I was not live because uh um of um of for private reasons. Um but today I'm again live here. Um and one among one of the things that I would like to show you I'd like to put this under the stereo microscope.

[00:01:46]There's been a request a couple of weeks ago that I do a little bit more stereo microscopy um again. So, why not do that? This one I collected just a few hours ago, but you can see it's a a little bit dried up already. Um and uh yeah, we're going to put this under the microscope um a little bit here. Um I found on this plant sample I found a couple of spiders, two spiders. I'm also going to look at this. And then of course um also a little bit of a recap from last week. Um I want to again put some the water sample with the psiliates that I've got over here under the microscope to see how that sample has developed and we're going to look at a few slides that we prepared two weeks ago and to see how they are actually looking um if because actually um their quality has degraded also a little bit.

[00:02:30]Um so for this reason we're going to yeah I'm going to do a collection of a variety of different things. As always a welcome all around the world. I'm not going to go through the chat. Uh um but uh essentially yeah, hello everyone. Um and um if you have any uh comments or questions, please uh feel free to write them in the chat. Um I will occasionally have a look at the chat and also try to answer some of the questions. So um this is stinging nettle of course we all know. Look, there's another plant over here. Um is not part of it. It's a different one. Um of course we all know that when we touch it then actually sometimes it can hurt. Um, so why is that? Well, because it stings obviously and there is a a substance, an acid in there, um, where basically, uh, yeah, it starts to hurt a little bit. And, um, I'm just going to show it to you directly. The the answer to this mystery, which is not really a mystery.

[00:03:26]I already put it under the microscope.

[00:03:28]Here it is. And that's already the answer to the question. This is the reason why the stinging nettle stings because you've got those little little spikes. Yeah, especially on on on the stem. Okay. Um, so let's see if we can go in yet further with the Yeah. No, I'm going to show you the Yeah. the low magnification first. Right. This is how it looks like. And you can see that over here on the stem and also here on the side of the leaves. Uh yeah, sometimes you have to go into focus. You're able to see that essentially. Yeah. Um they're quite spiky here, right? Um and uh so this is basically the reason and I I want to show you something here. Uh let's take take those big big ones over here. What actually happens when you touch them? Um unfortunately I was not able to see it this time. Um it depends a little bit maybe how fresh the plant is. But I've got a a pin here right here. This is here is a pin a regular pin as used in sewing. And look, look at this. What I here just for size comparison, right? Look what happens when you touch it. They're pretty flexible, right? Actually, they look kind of soft. And I've done this already before. And then um I was able to actually see that there is a a droplet of of liquid actually came out.

[00:04:48]Unfortunately, uh unfortunately, I'm not able to see that here. Okay. But I would like to try the following. I would actually try to cut this off. And I would like to try to make also a slide um and to have a look at this uh using also my compound microscope. Yeah. Yeah.

[00:05:06]So um essentially what this um means and is is that if you actually pick those sting nettles then you actually don't touch it like this but actually you have to kind of stroke it a little bit and then touch it because this will then um uh bend over the spikes so that they cannot puncture your skin. Yeah. So this is Yeah. Um, you want to have some I I see that some of you want to have some cross-sections of the stem. And you know what I say?

[00:05:32]Why not? Okay, I have no problems. Uh, let's do some cross-sections then, um, of the stem as well. Um, I would like to, however, try to put one of those um, yeah, spikes here a little bit under the microscope as well. Okay. What I'm going to do is right now is I did prepare a short video as well. Here it is. So, this is basically was in the just in the afternoon uh, today. you behind uh yeah where I live in my behind my apartment there's this uh um yeah just as a size comparison how big they actually are right um they're almost my size and uh what I however did is I tried to pick some some smaller ones some fresh ones here of course with a scissor because I did not want to actually uh touch touch them myself right yeah and then the video starts to loop um again so sometimes you can actually also see that there are some holes in the stinging nettle over here. You see the and these tiny holes here are usually because of caterpillars or maybe other insects that have actually eaten um some of those stinging nettles. Okay, so that's a little bit the the the um yeah the background here. Um so when we what we can do is I have to dig out my I have to find my micro again and here it is. So let's try to again make then later a um a little um crosssection of the stinging metal which I don't remember that I have ever done before. So I'll I'm just going to get everything prepared here.

[00:07:05]Here it is. Okay. Got got that stuff here ready. You see um I need I need this here. Remember and the micro. Um, but what what I would like to do first is um and that's going to be maybe the more difficult part is I actually would like to put some of those um where is this uh yeah those things here under the microscope. So what I need to do is I somehow need to be able to cut this off carefully and that's going to be slight a slight challenge. So I'm going to go back to the desk view.

[00:07:36]Yeah.

[00:07:37]So yeah, eating is also possible. Um, not only that, some people make uh um actually uh tea. You can actually make uh uh you use fresh ones. You dry them and then you can make tea. Actually, apparently quite healthy. And this is now going to be the big challenge. And I have no idea how I'm going to do that.

[00:07:52]How am I supposed to cut this off here?

[00:07:54]Those tiny um those tiny things here. I have really no idea. So, what I'm going to try to do is I'm going to simply try to maybe I'm going to grab it here.

[00:08:07]Do the easy way first. I'm just going to try to You don't see it here. Just take part of the stem here first.

[00:08:19]Another question is is um how am I supposed to just get the I have really guys uh folks I have really no idea.

[00:08:25]Okay, but you see over here the very fine um yeah spikes and I'm going to maybe try to cut it longitudinally.

[00:08:37]Okay. and then hope for the best.

[00:08:43]Here we go. I just I'm look I was looking for my needle again and I misplaced the needle. Here it is over here.

[00:08:54]Okay.

[00:08:56]Yeah. So, it's out of focus. Bad. Bad.

[00:08:59]Bad. Bad. Okay.

[00:09:02]So, and I don't know if this is actually thin enough. So I see I kind of cut the stem not longitudinally um because it was too difficult for me to actually get the just and then let's hope for the best that this actually will be sufficiently thin that we're actually able to see yeah this um I'm now going to do a very quick check without any mounting medium without any water. I'm just going to put it directly under the microscope.

[00:09:32]I need to turn on the lights as well.

[00:09:34]Let's just uh do a first quick quality check.

[00:09:40]And actually this is it.

[00:09:45]This is actually ah look at this. Look at this. So this is actually not so bad.

[00:09:56]Not so bad. Not so bad. So this is again this is without water, without anything.

[00:10:02]And it's not flat. Therefore, it's you see if I focus all the way through here.

[00:10:09]Yeah. This ah this is a tiny droplet maybe here at the very Yeah. Yeah. There seems to be spines on the spines. I don't know if this is Yeah. So, what I'm going to do now is I'm going to of course going to try to compress this a little bit. This is going to be a little bit difficult because it's fairly thick as a specimen. Um but let's give it a try. in any case. What I need is is of course a little bit of water.

[00:10:34]So, and then I'm just going to be pretty cruel and brutal. I'm just going to press down on it and I'm going to compress it and hope that uh yeah, this will then uh make sure that this is going to be sufficiently flat.

[00:10:50]So, cover glass goes on top here. You see it is fairly thick. So, um, I now need to I need a solid I think here. And I'm going to simply press down on it now.

[00:11:07]Kind of compressing the specimen and hoping that I'm able to see something here. That is a really a question of luck. Now here, let's see if we're able to find it. Compression specimens are nothing uncommon.

[00:11:27]And we were lucky. We were lucky. Gee, am I relieved. Here it is. You see, there is a little bit of a Yeah. Yeah.

[00:11:36]Um over here. Let's see see if there's another one over here. Ah, this one is actually Look, this one is actually quite nice.

[00:11:44]You see it came off here, right? So, yeah. And here it is one of those uh Yeah. And here you see actually here on the stem there many more.

[00:11:55]Yeah. And now you can actually also see the individual cells. Here's a huge one.

[00:12:00]Again, the one from before.

[00:12:03]It's actually quite quite a a good uh thing here. You can also see the individual cells here.

[00:12:12]So, I'm actually quite happy. So what I've done is this is called a compression specimen, right? I've already made it very thin, but then I simply pressed down on it, put a cover glass on top, and this looks of course my favorite tissue, the xyllem.

[00:12:28]Yeah, this is okay. I'll just show you a little bit here. I mean, every time we look at plants, um um you see this the it's a little bit spiral-shaped structure, right? That's uh these are the vessels that actually carry water up a plant. Let me turn on Yeah. Yeah. It's these are actually spiral-shaped Yeah.

[00:12:50]reinforcements in the cell wall. It's called the xyllem. And you can actually see those dark areas. That's air that's that's in it. Right. Um so I'm quite happy to be able to see that. But let's and look over here directly also on the on the uh surface here. You can also see those little spikes here. little. Yeah, it's quite nice.

[00:13:12]Um, so there a comment here. There seem to be two different sizes. Are the large on the stinging ones or both? Uh, basically I'd have to guess now, but uh I know that there are the larger ones on the side and and then there are um however over here um plenty ones plenty other ones also around it. I suppose maybe this just a question of of um um of where they grow. But you see here, this is a No, that's not one. Here it starts.

[00:13:45]Yeah. This is a huge one over here. I mean, it it's so different in in size that it must be a different kind.

[00:13:53]Yeah. Um and something that I'm I don't I'm not able to see that here, but maybe there's you're able to see a little bit of a canal on the inside where the liquid Yeah.

[00:14:04]is actually passed out. No, can't see that quite well here. Let's turn on DIC just for the fun of it to give it a little more color.

[00:14:17]Look at this. This is actually quite quite surprisingly good because the refractive uh difference in refractive index it actually looks pretty nice.

[00:14:30]But let's look at the other ones that are now found on the surface here. Where are they? Here's one.

[00:14:37]Do we focus? Yeah. I mean, they definitely look like different kinds.

[00:14:43]Yeah. Yeah. Ah, look at this. Ah, also fun. Look, you got to be watch carefully. That's a These are stonemates. Do you see those things here? Uh, okay. My mouse is a little bit acting up.

[00:14:58]Now it goes again. You see this here, right? There's a little tiny hole here.

[00:15:01]These are stomates, which are openings.

[00:15:03]Um, which I kind of find interesting because this I'm looking right now at a stem, right? They usually you can find those stomates um on the bottom side of a um of a leaf. Yeah.

[00:15:16]I kind of like this. Yeah.

[00:15:19]So, staining might uh Yeah, exactly. Um, look, also over here. I mean, a couple of years ago, I did make a video and I was quite lucky because I actually was able to see how there was a little droplet of liquid some coming out of some of those spikes.

[00:15:36]But the thing that fascinates me is is how extremely thin or pointed they are.

[00:15:40]Right.

[00:15:43]again over here in a nice uh cell. And now you see also here the exylm pretty nicely, you know, the the the the spiral-shaped reinforcements. Yeah.

[00:15:52]Yeah. So that's that's pretty Yeah, I'm pretty happy with the result. Yeah. Here also the cells are visible.

[00:16:02]Oh, look at this one is a little bit bent.

[00:16:07]Sometimes I feel we have a I don't know today as I was preparing a little bit.

[00:16:13]Uh I wasn't preparing a lot but as I was collecting the the the plants and everything and and doing a couple of of of um first observations I was kind of wondering myself man we we've got a weird hobby being fascinated but on the other hand honestly I consider nature very beautiful you know. Yeah. and and the microscope as a as a as a tool to access a completely different view of the environment in nature. I think that's pretty fun. Yeah.

[00:16:44]The green chloroplasts. Yeah. So, generally um Yeah. So, you see that is um um very briefly um a a um a nice uh easy way. You just take a small sample of of of the plant and then you could simply compress it and uh you kind of squash it flat. Yeah. Um so without cutting and this way um we're also able to see quite a bit here. Yeah. So here the cells quite nicely visible. Yeah.

[00:17:13]Yeah. Um so let's move on. There has been the the the the request to make a crosssection of the stem. This is going to be a painful experience now for me.

[00:17:23]Yeah. Look at this. Yeah. They can even see the cell organels here.

[00:17:30]Ah, there's another one here. Oh, two of them. Look.

[00:17:38]I'm just reading this.

[00:17:42]Yeah. The the hobby you pass on is all awesome. Yes. Thank you for that. Thank you as well. To me, having Tik Tok as a hobby is weirder than our microscopy hobby. Honestly, um I've been um the whole thing with social media is uh on one hand a blessing and and a problem.

[00:18:02]Um the blessing of course is that it's easy nowadays to make videos and and to have a community and to kind of share the hobby of microscopy.

[00:18:11]Oh, there's a firework going on on the outside here. Today is Saturday. Um sometimes uh when I don't know if you're able to hear it uh it's not a thunderstorm but sometimes people are marrying on on a Saturday here and then they have on Saturday evening they have a firework so maybe you're able to hear that. Yeah. Yeah. So quite quite yeah I just said the following this uh this whole thing with social media on one hand is a curse and a blessing. a blessing of course because it's not easily possible to share a hobby like microscopy or whatever but then on the other hand I've heard that a lot of uh hobbies um these days um start to disappear uh because u people are more and more on social media. Yeah. So yeah so it it's um yeah marriage. Yes. Yeah. Every now and then on a Saturday they have a very short some people are organizing a very short firework and there was actually a thunderstorm just half an hour ago. I was a little bit worried that we're going to have a power shortage uh but outage but nothing like that happened luckily. So yeah. So you know what um let let's try the painful thing. Let's try to make a cross-section. Okay. Um honestly I have also not made a cross-section yet of a stinging nettle.

[00:19:29]Um, sometimes it's also one of the reasons why I like doing this uh this live stream is is because um yeah, I also get to do things that I normally wouldn't do. Um, so what I'm going to do now is I need I need a solid surface because um the surface that I have here is is actually a softer plastic writing surface to kind of protect the table and to give it a nicer background color.

[00:19:53]Yeah. But this also means that I cannot cut anything on here. So, I'm going to do it like this.

[00:20:02]Okay, here we go.

[00:20:05]Let's remove this here. And I need to put this now into one of those specimen holders. Um, yeah, if you've joined me already previously, you know that I have uh 3D printed several of these specimen holders. The two holes here in the center, for those of you have not seen this yet, the two holes in the center are simply for taking it out of the microtome. You're just going to see in a second how this works here. And you've got I've got one, two, three, four different diameters for different stem sizes. And I'll be using I don't know, maybe this one over here. Yeah, this one here on the side. Um, and I think this one actually might go in here. Yeah.

[00:20:42]See, it's able to fit without problem.

[00:20:46]And I'm going to take over here a a pin.

[00:20:52]I'm going to push it all the way through to hold it in place. And I hope that I'm able to do that because when I So here we go.

[00:21:02]Oh, this is a Here we go. Yes. All the way. All the way in. All the way in. All the way in.

[00:21:12]I don't know. This is a problem. I just realized because this pin head is still sticking out.

[00:21:19]Ah, this is bad. So, I won't be able I won't be able to get it. So I um So I won't be able to fit it into the microtome. That's a bad thing here. So what I'm going to do maybe I'm going to try to switch this over to the other one. It's a little bit larger.

[00:21:39]So let's try this here.

[00:21:43]Let's put this in here. Push this all the way in.

[00:21:54]Yeah, it's not the the pin is now not long enough.

[00:21:58]Okay, so this is a little bit of an issue. Not to worry. Um I'm just going to put it back into this one over here.

[00:22:05]No, which one was it? This one over here, maybe. No, let's do this one. It's a little bit Yeah, it's a little bit tighter. And uh I'll put it now into the microtome fell out.

[00:22:21]And I'm going to turn it. I'm not going to clamp it to my table. Okay. I'm just I have to turn this. I have to lower um the piston here. By turning it, I'm lowering this piston.

[00:22:35]Okay.

[00:22:38]So, um let's make it a little smaller.

[00:22:42]Right. So, this one goes in here.

[00:22:48]So, here we go.

[00:22:50]going to put it carefully in here.

[00:22:55]Uh now it is definitely too too deep inside.

[00:23:00]Yeah. So let's uh I'm turning it now.

[00:23:06]And it's slowly being pushed out. So maybe I can keep it like this here. I need my sharp uh knife. And let's see if the first cut is always a problem.

[00:23:19]You see it's a tiny amount. And I need um also a little bit of water because those cross sections they dry out very quickly.

[00:23:29]So the water is up here.

[00:23:34]And uh then so let's see if I'm able to get this here. Uh this was too thin.

[00:23:52]also too thin.

[00:24:02]Okay, maybe maybe this actually worked here. Quickly into the water.

[00:24:10]You know what? No, I'm not going to put it into the water down here. I'm going to actually put it directly on a microscope slide.

[00:24:17]I think we're just going to save uh the little intermediate step here.

[00:24:22]So I would say let's do just like last week. I'm just going to save this intermediate step and let's add the water directly and let's put this in here. Okay, maybe this works better.

[00:24:44]And Yes, I already mentioned before that the success of this is a question of trial and error.

[00:25:02]It's too thin.

[00:25:09]And I will also tell you something else that I've been thinking about. um not had the time yet to try that, but I'm just throwing it out to you. Um I've been thinking about actually maybe it is somehow possible. I know there these knives, the ultrasound knives, basically they have some kind of a pto electric thing so that the knife is vibrating. Um basically kitchen knives. um they're pretty expensive and I was kind of wondering if it's also not possible to add some kind of a vibrating mechanism or like an ultrasound mechanism to one of these things here like um some kind of a piet quartz or something like that which causes it to vibrate um to cut it more easily. Um just an idea um yeah so here that's another one.

[00:25:59]Here we go. I'm just going to make another cut.

[00:26:07]This one was not so nice.

[00:26:17]And I think I'm just going to yes, leave it then as it is. Um, again, in the context of a live stream like this, um, I cannot take the same amount of time that I normally usually would take. Um, it's a little bit more like a quick demonstration of what's possible.

[00:26:35]And, uh, yeah, sometimes the quality is not the best.

[00:26:42]Yeah. Look, look at this here. Do you actually notice how dirty this one is?

[00:26:45]This is there's a reason to that because I actually washed those um cover glasses, but there is some deposit of calcium carbonate. Some water stains are still on here. So, I'm going to quickly also wipe it.

[00:27:01]Yeah.

[00:27:08]Simply to make it a little bit cleaner.

[00:27:15]I generally try to reuse uh as many of the cover glasses and slides as possible. So, let's drop it on here.

[00:27:24]Yeah, still very thick, right? So, I need definitely I do need more water.

[00:27:35]Let capillary action to the rest.

[00:27:45]Okay, let's give it a let's give it a short try.

[00:27:49]So, the specimen is fairly thick, unfortunately.

[00:27:54]Okay, so let's start off with the a low magnification and let's it's a 10 times.

[00:28:03]Yeah, I need to make it a little bit d.

[00:28:09]Here we go.

[00:28:12]Yeah, of course, as always, there are some some air bubbles. Ah, look at this.

[00:28:17]Are we not lucky? Look. Yeah, look. Now, you can also see those spikes here on the side.

[00:28:25]That's actually quite nice. Yeah, this one here is a fairly good cross-section.

[00:28:30]Look.

[00:28:32]And here on the side, we see we're able to see those spikes again.

[00:28:40]Yeah, of course, making that permanent slide of this would be quite nice, huh?

[00:28:46]Yeah, the quartz crystal. It's uh on the microphone will vibrate on a micro and cut better. That that that's actually this was kind of my idea. Some kind of a some kind of a quartz or or pzo quartz or something like this. Yeah. Um so this is a little bit something that uh can is worth trying.

[00:29:05]Yep. Here we go.

[00:29:08]But maybe look uh do you actually see this here? There is indeed a this might actually show that it's a hollow. Let me turn on the arrow again. Usually that's the reason why air bubbles sometimes are kind of useful because this air bubble over here means that probably this this spine here is a this spike is a little bit hollow, right? Also over here is an air bubble.

[00:29:32]Um yeah it's uh this irritant I think if I remember correctly isn't it formic acid.

[00:29:41]Look here also very nice. I love it. I love it. I love it. I love it.

[00:29:48]What do I see here?

[00:29:51]What is this here? Let's open it a little bit.

[00:29:55]Of course.

[00:29:57]Ah monocult or dieot. Yes, a die cot. I will explain why. Look at this. This here, this is that's of course galm, right? Yeah, that's of course galm. Yeah.

[00:30:12]So, um and let's uh talk a little bit about this monocott thingy. Um you see that the two two types of flowering flowering plants are either the monocottas or the d cautillus plants. Um the cotalons are the first leaves that are formed.

[00:30:28]Um and this is a clearly a dicot plant.

[00:30:32]Uh why? Because the vascular bundles basically the xylem and the phem are arranged in a nice circular pattern. So yeah. So see you see those vascular bundles here. Again my mouse is acting up a little bit.

[00:30:50]Maybe the battery. I've got a wireless mouse. These are the vascular bundles.

[00:30:53]You see they're kind of arranged in a ring shaped here. Yeah. It's very typical of a dicot plant. While in a monocott like uh for example onions and liies and so on, they have those vascular bundles distributed right around in throughout the stem and they're not arranged in this nice pattern. Yeah. So that's actually one reason why it's a dicot. And yet another one obviously is over here. We just look at the the the the vascular. You see it's branched, right?

[00:31:24]That's also very typical of a dicot.

[00:31:26]While for example corn, yeah, and grasses and wheat and and and the flowers liies, they have all of those veins that are basically in parallel, right? So that's why these long elongated leaves. Yeah. These are all monocots. Yeah. And if you've got those branched venations basically um for transporting the water, then it's also dicot. Yeah. Yeah. Histamine. Yeah.

[00:31:49]Formic acid. Yes. Yes. Yeah. Um yeah.

[00:31:52]Histamine. It's causes this uh immune re reaction. Yeah. Um so um yeah, I was just reading a little bit here. Yeah.

[00:32:04]Ah okay. I got I sent you some image of my upgrade through email. Thank you very much. Um did not check yet. Yeah. Yeah.

[00:32:17]Kelzar. Ah okay. Sicily acid. Uhhuh.

[00:32:20]Yeah. Maybe maybe it is a maybe it's indeed a combination of several things could be. So um yeah so this is uh again um yeah a very nice yeah more or less yeah I think in in any case more or less instructive and again we are able to see and this is the thing that kind of makes me happy that uh the cross-sections that you're able to make with this micro indeed are thin enough that you are actually able to see um individual cells in a way that they don't overlap. I just show this to you again. If I focus through here, you see it's blurry, out of focus, then it goes in focus, but it's basically still the same cell walls. Yeah. So, this means that the the Yeah, it's probably around one maximum, maybe two cell layers thick. So, I'm I'm quite happy that the Yeah. the the cross-section is fairly um yeah, not only consistent, but also fairly thin.

[00:33:22]Um, let me turn the the No, let's move the arrow away here again a little bit so it doesn't disturb too much bubble wrap. Yes.

[00:33:32]Again, ah, look here again the island. It kind of shows how much stronger it is. Um, because it kind of it's almost like a wire, right?

[00:33:41]So, yeah.

[00:33:45]So, what time is it? Okay, half an hour.

[00:33:47]Now, I'm going to slowly maybe move ahead a little bit. Um, I do want to show you uh just for the fun of it.

[00:33:55]Yeah, I'm I'm just going to show you what else I found now under the stereo microscope. Let let me turn on the stereo microscope.

[00:34:03]Basically, together with together with Let me always start with a low magnification. Together with the the plant I found, where is it? I found this here.

[00:34:14]And of course, I had to immediately have a look at it. There are two spiders in here. This one is actually not looking at me.

[00:34:30]Yeah, they were running around just a minute ago.

[00:34:35]Yeah. With it basically.

[00:34:42]Yeah. That's uh what you Yeah. So that's the smaller one. Uh actually I was hoping to see the eyes of it.

[00:34:48]Because uh of course spiders have lens eyes and somewhere over here is the other one. I've got a lid on top now so that they can't run away.

[00:35:00]Yeah, maybe I'm just also going to here. This one is now running.

[00:35:12]It's crawling up all the time. No, this one here is now over here.

[00:35:17]Let's see if it starts to Yeah. So, this is also Yeah. something that uh I like to do every now and then. Sometimes I have occasional discoveries like those spiders or um sometimes also insects and so on and then I like to simply put them under the microscope and observe them a little bit.

[00:35:37]But somehow instinctively they ah here here we able to see the eyes up and it fell off.

[00:35:45]Yeah. the the sides of the um of the petra dish are quite slippery to a certain extent. I almost not dare to say it to a certain extent they do look kind of cute. Um I don't like spiders particularly obviously but when you actually magnify when you put spiders under the stereo microscope they look less scary than some of the insects. Some of the insects with their I don't know mandibles and big antenna and so on look actually more like aliens. Spiders act and scary spiders actually uh look less scary when you magnify them I think.

[00:36:26]Yeah.

[00:36:29]Yeah.

[00:36:32]Um the thing is the following. Um when we're doing some insect obser Okay.

[00:36:37]Spiders are not insects but you get the idea. when we do some insect observations with the students uh in school when we catch insects and also put them under the microscope um yeah of course students at the very at the beginning they're of course disgusted and ah yeah but at the same time there is this huge fascination that still of the complexity and the beauty yeah of of those animals yeah because if you just zoom in it's it's yeah incredibly complex yeah And that's also one of the things that fascinates me. Yeah. Peacock spiders. Uhhuh.

[00:37:17]Yeah.

[00:37:19]So, yeah, it's quite uh quite quite interesting. And you know what I'm going to try to do? In any case, let's get I'm going to remove the lid now. And this should give us a slightly better image quality. Of course, they might escape, but it's okay.

[00:37:38]Ah, here it is. Yeah, it's trying to escape.

[00:37:43]No, it didn't.

[00:37:45]Let's go down with the magnification again. And the two spiders seem to be ignoring each other. I've heard that sometimes if two spiders encounter each other, they might actually not like that. They might not like each other.

[00:37:58]Let's look for the other one.

[00:38:01]Yeah, it's over there. Yeah, you get the idea. Okay, so what I'll be doing, it's difficult to find. What I'll be doing is of course I'll be trying to I'll be releasing them again obviously. But it was kind of a by catcha with the with the plant. Yeah.

[00:38:18]Yeah.

[00:38:20]So that's every now and then when they start resting this guy is a little bit Yeah. Okay. I think I think enough.

[00:38:31]Yeah. It's the uh moving objects are always a little bit difficult to observe obviously. So, let's put a lid again on top.

[00:38:39]And here we are again. Okay. So, um what I want to do now is maybe um look at a few slides from last week. Okay. No. Um not yet. I'll have a quick look uh um of what some of the uh comments are. Okay.

[00:38:55]The brand of my stereo microscope. Okay.

[00:38:58]I'll tell you the brand. The brand it's it's a Euromax. Um and the model is uh Nexus Nexus Zoom. Um however, it's like this that many uh stereo microscopes are actually quite similar to each other.

[00:39:12]Yeah. Um how long can you keep a semi-permanent slide of onion plasmolysis semi-permanent? Honestly, if you want to keep slides for a longer time, you have to make sure that they're free of water. Um and as soon as water is a little bit present like semi-permanent um there is always the danger that it's going to start decomposing that that's the main problem. Um as soon as the moisture is present then this can actually mean maybe fungi will start to grow. It might start decomposing. So um yeah so difficult to say it depends a little bit on the storage conditions but u um it's limited in time. Yeah. Yeah. So, I will quickly have a look. There are not so many questions for me. Yeah. Uh, how long would it take? Can you cut them with I can you clean them? Oh. Uh, I'm I don't quite know what. Can you clean them with isopropanol as well? Oh, you mean that the slides that I I I've been cleaning?

[00:40:24]Okay. Um, or the cover glasses. I think this refers a little bit because I've been cleaning. Um, generally it's like this that um the if you were if your question was about the cover glasses.

[00:40:33]Um, if you've got those water stains on on some of those like this one, these are some pretty bad ones, right? Um, then this is um this is actually calcium carbonate. Um, and then you have to use acid like for example vinegar or something like that. Uh but isopropanol is or any other alcohol is only going to be useful if you've got fats and oils.

[00:40:56]But generally there are not so many unless you've got really fatty fingers or something like that or greasy fingers. Um it's not going to um isopropanol is probably not going to remove uh water stains very well. Um yeah, it's uh actually more um suitable if you use uh let's say vinegar or other weak acids. Yeah. Um there are Yeah. Um, do you run the cover glasses also in the dishwasher? The short answer is is no because they're going to be flying around. However, what I have done is the following. Um, and I'm also doing that with the other slides. Um, I'm not put I don't put them directly into the dishwasher, but I put the slides into um a plastic box uh with hot water and then some dishwashing powder. So, while I don't use the dishwasher itself, I will use dishwashing powder. And I found this to be very effective. Okay. And then of course I'm rinsing each slide individually. Yeah. And it could maybe be that I also did not rinse those properly. Maybe there's even some dishwashing powder left on here. Not not a good idea. It's bad for the microorganisms. Okay. So um yeah.

[00:42:06]Yeah. Exactly. Lime skill it's called this. Yeah. Calcium carbonate. So what I'm going to do now is the following.

[00:42:12]Um, I'm going to give you a quick run through uh through a couple of other slides. Uh, the ones that we made before, at least some of them.

[00:42:22]Um, some of them are kind of two weeks old or so. And I've made them just to show them here. And I'm not going to spend a lot of time on them. It's just a very quick check.

[00:42:36]So, I've made some uh cross sections of uodia and uh I've mounted them in glycerin gelatin and indeed the specimen degraded. I'm just going to show that to you. And then I think two or three weeks ago what I've done is I've tried different uh mounting media as well um over here um on algae.

[00:42:58]So this one is a a glue that's um Elmo's PVA glue and that's also glycerin gelatin. So I tried different mounting media as well and we're going to have a quick look here uh because specifically disappointing is the leave of Ilodia which was actually quite uh nice and green and crisp but uh kind of degraded now a little bit. I just want to show this to you. So it kind of shows that um not all permanent slice are made for eternity unfortunately.

[00:43:26]So there's lots of dirt here.

[00:43:29]Yeah. So, and the thing that you might notice is that essentially, let's remove the DIC.

[00:43:37]It significantly lost in color.

[00:43:40]Yeah. I mean, it's still a little bit green, but by far not as green as it used to be, and it almost looks a little bit like the contents of the cells has shrunk a little bit. It does not look quite as as as fresh anymore and and as crisp. Yeah. So this uh basically yes I labeled the slice. Um so this kind of shows that um yeah even though it's only about two weeks old it already started to yeah to lose a little bit of of of quality. Yeah. So if you remember that the chloroplast were really nicely visible and then now they they're kind of very deformed barely visible. So that's that's one thing. Uh over here um what is this here? the crosssections of of the water plant. The stem cross-section.

[00:44:28]Let's find find those.

[00:44:33]You always start with a low magnification maybe.

[00:44:36]Here we go.

[00:44:42]Was this a stem cross-section? Yeah.

[00:44:44]Let's make Let's try to find another one over here. This one over here.

[00:44:48]And maybe you notice something else.

[00:44:51]What else do you notice? Okay, a lot of bubbles obviously, but there is something else that you might notice and that is the color. You actually notice now that it looks kind of reddish purplish pink pinkish actually.

[00:45:07]And the reason why that is is because the glycerin gelatin had a stain added and the stain now had enough time to actually stain the plant.

[00:45:18]So because this uh glycerin gelatin I I've actually bought to mount pollen grains um to to also stain the pollen um and now you can see that it actually also stained yeah the cross-section here as well. So that's why it kind of turned a little bit reddish in color.

[00:45:38]Yeah. And look at all of those bubbles that started to appear now. Yeah. So that mean basically means that there is indeed a a somewhat of a change in in um yeah in specimen stability. And here now this is basically these were now the algae um which I I think these were the algae which I mounted in different types of glue uh water-based glue. Um and let's see here again. I have to always adjust this.

[00:46:08]Yeah, it's kind of very dirty.

[00:46:12]Here we go.

[00:46:14]Yeah.

[00:46:16]So, we have to go up with let's try to find a place where the density is a little bit higher.

[00:46:22]Here it is. So, let's go up with the magnification again. Um, this by the way is again bright field. So, no optical staining here. Let's go up yet further. those string-like structures, many of them cyanabacteria.

[00:46:43]But if you actually remember a little bit of how it looked like two weeks ago with a fresh sample, um yeah, no comparison. The fresh sample is so much nicer and better than this one. So, this basically means that even here we have a little bit of a degrading of um yeah, of specimen quality. Um let's try the other glue over here.

[00:47:06]Okay.

[00:47:08]Yeah. Here is one seems to be a little bit of course depends also on on the specimen concentration.

[00:47:16]Yeah. But it's also a water-based glue.

[00:47:20]It's Elmer's PVA glue.

[00:47:23]And let's now try if I'm able to find it. Now this one here is again glycerin gelatin.

[00:47:31]Yeah.

[00:47:34]And uh you can see that the contrast yeah is alo different here.

[00:47:41]So you see that a lot of again is an experimentation but generally I would recommend I mean opinions vary. Um, I would probably recommend that uh making permanently mounted slides of algae and water organisms. Of course, please try it. But yeah, it's very static. There is no movement. And actually, the thing that makes uh it so much more interesting is actually the movement that's going on.

[00:48:14]Yeah. And of course, we don't see that.

[00:48:16]Yeah. Stenadesimus. Exactly. Uh let's let's zoom in. Send a decimus is still recognizable. So basically, but again much nicer in a fresh sample.

[00:48:30]This one over here. These are basically Yeah. mini colony. And there are those four extensions here. Yeah. Very often they appear in colonies of of of four four cells.

[00:48:42]But the many other cells here in the background, they start to kind of lose their color. They start to bleach a little bit. Um nothing unusual because of course uh um pigments very often start to to bleach. Yeah. Um I think it was a couple of weeks ago when I showed you some slides that were over 30 years old. Um they were almost completely free of color.

[00:49:06]Okay. just yeah a little bit of how do you say um yeah evaluation on how the slide quality actually is. And what I'm going to do now of course um as well is is I I'd like to have now also a little bit of a check on how the um enrichment culture is doing.

[00:49:28]Okay. Um because again remember I think two or three weeks ago I added uh some wheat grains into this water sample then and it's starting to look very oh very disgusting. It's actually a good sign.

[00:49:46]Yeah. So for those of you who were not there when I've done that um if you uh what I have done is I've taken these are wheat grains right uh cereals in other words and I have taken one or two of them and I crushed them between two spoons and simply dropped it into a water sample and what will happen then is that uh siliates and and flagagillates and parramsia and hopefully rotifers they will start to to grow here. Um it looks very cloudy. This basically means it's uh there are probably also plenty of bacteria present. Um and for this reason I'm going to now take a small sample and I would like to check now how this actually um yeah looks like um under the microscope because um every yeah there's a progression um um of organisms and every week it might look a little bit different. So, what I'm going to do now because it's somewhat a little bit deeper down actually I can use I can try to use this here as well. So, um and then of course I want to be a little bit careful because there of course bacteria and all this stuff on the tip. I'm going to actually go directly into here. I didn't catch anything.

[00:51:02]I don't know if I actually caught a lot.

[00:51:08]No, I think the problem is is that the tip is a little bit too small in diameter.

[00:51:19]H I mean there will be already plenty of stuff in here, but I was actually hoping maybe what I'm going to do now is the following. I'm going to take a slightly larger pipet. Um, and I'm going to take it at the largest sample.

[00:51:40]This is pretty disgusting. And that's not that's nice.

[00:51:45]Is too much.

[00:51:47]Way too much.

[00:51:50]Ah, won't come off here. Now, now it's off. Um, I have a problem. The problem is is that it's way too much. So, I'm going to now do the not good. I need to use a fairly large cover glass. That's not the problem, but it's still too much liquid in here. Um, where are my large cover glasses?

[00:52:20]Here they are. And I need to remove quite a bit of the liquid otherwise.

[00:52:29]And uh if you remember also when I started to make the sample yeah there were very few green there was a very few green stuff in there. Uh so also the algae and whatever not started to grow here. And I'm now going to remove quite a bit of this liquid again.

[00:52:49]Going to put it back into the jar because otherwise it's going to be way too flooded.

[00:53:02]So, let's see how this works.

[00:53:13]Yeah, we have to throw away the tip.

[00:53:17]And let's give it a try now. Yep, I think this should be uh okay. There is no liquid spilling out.

[00:53:28]And um yeah, let's see what we're able to find here.

[00:53:42]Okay, this is now at four times with a four times objective. Yeah, there's some movement going on here. Um let's go up with the magnification here.

[00:53:54]Yeah. So the sample is quite healthy and alive.

[00:53:59]Um again a little bit my disappointment is I was hoping to find more siliates like or parramia specifically um which are quite large um but over here we've got other specimens.

[00:54:14]Lots of rotifers really. Wow. Lots of rotifers.

[00:54:21]Um yeah, so it really depends on on what organisms are present in the first place and then you're simply enriching those.

[00:54:28]So um with a different water sample you might have got different different ones.

[00:54:32]Actually this is quite cute.

[00:54:35]There's lots of rotifers here.

[00:54:39]Yeah.

[00:54:42]Whole whole colony or family of them.

[00:54:47]Look at this. Yeah. So, the specimen, yeah, the microscope slide is also sufficiently thin so that they're all pretty much in focus.

[00:54:57]Let's remove the arrow again. It disturbs me.

[00:55:00]Let's add a little bit of color. Let's see if this actually makes a difference.

[00:55:04]No, not so much.

[00:55:06]Yeah, but you actually now see how how green the the the algae and so on, how green they are. Yeah. And how much color they have lost. Yeah. in the permanent slide.

[00:55:26]What are those circular shaped waterers?

[00:55:28]I'd have to check my identification book. Um, yeah, what what they could be.

[00:55:36]Those lines that you see in the background, those fine lines are most likely cyanobacteria obviously. And here they are all crammed together having a more or less happy life not knowing that they're now being watched by I don't know how many people. A lot of people do they have other things to worry about. Yeah. Again those the algae over here. So let's have a look uh again a lower magnification a little bit and what we're able if they're able to turn it down this whole thing here.

[00:56:09]So that's why I always recommend if you um have problems finding um interesting things, take some solid material. Very often living things are actually next to to some some debris and solid material.

[00:56:21]Um Oliver, I'm just reading the the comments here. Oliver, when making permanent slides of rotifers, it's difficult that when they feel the slide is drying out, they enter to a phase that they change their shapes into balls and it's kind of unrecognizable. Yeah.

[00:56:38]Yeah. So this is generally a problem and I also uploaded very recently a couple of days ago another video where I tried to make a permanently mounted slide of a sample like this. Um and you have to dry it and then of course the organisms they lose their shape.

[00:56:54]Um yeah, off topic. Don't know if you saw it. I recently did a 70 plus hour time lapse of the purple amiebas. Highly recommend you to check it out when you have some free time. I suppose it's it's on your YouTube channel.

[00:57:08]then I'll check it out. Okay. Thank you for the for the tip.

[00:57:15]So, what else is there? Yes. Could this be here? I know. I wonder.

[00:57:23]Look, let's let's zoom in here.

[00:57:27]Let's zoom in here. Do you see circle in the center?

[00:57:32]Right in the center. I have a suspicion and my suspicion might be actually correct that we're looking at an amoeba here.

[00:57:48]Yep.

[00:57:49]Yeah.

[00:57:51]So, and 60 times.

[00:57:59]Yes. It's actually quite nice. Yeah. So, this seems to be an amu. You can actually see what it has eaten. Yeah.

[00:58:06]Yeah. But, uh, yeah.

[00:58:10]So, it should be actually able to change its shape. Yeah.

[00:58:14]Um, yeah. So, yeah. You see it's kind of those amoeba are actually quite uh nice to make time-lapse videos of because then and when you speed up the movement then actually you can actually see it much better how it starts to crawl along. But that is of course quite uh quite nicely visible. Yeah.

[00:58:40]Yeah. It's Yes, exactly. It seems to have eaten quite some something quite big.

[00:58:45]Yeah. So usually what they do is they take on the color of the food that they eat. So if you see that there's something green inside the amoeba, it's most likely because they've eaten some green algae.

[00:58:58]Yeah.

[00:59:00]Yeah. So this is uh usually um amoeba are more more difficult to find sometimes because they're easier to overlook because they don't move quite as as quickly. Yeah. So let's go down again with the Yeah.

[00:59:18]Yeah. Let's what else do are we able to find here? Of course, rotifers.

[00:59:26]Yeah, I mean again uh what I recommend is um is you just got to try.

[00:59:35]Every time when I've looked at water samples and made an enrichment culture culture, I found different I found different organisms.

[00:59:45]It really depends what's what's present in the first place. So this here is also quite nice and interesting to see. I gosh the dark it's too dark. It's too dark. Okay.

[00:59:55]So this is actually also something that you see quite frequently. Um here um again where is the arrow?

[01:00:04]This thing here again of course an amoeba right? Um not moving very quickly but this one is quite interesting. Those tiny little things here these are bacteria of course and this one here is green. So it's an algae and producing oxygen and uh very often you see that uh um you will then have bacteria gathering around u your algae because they need oxygen something you can see that quite often and um forgot the name of the scientist but this was actually a very remarkable experiment that what has been done back in the in the day um they've used different colors um of light uh to to shine it on those algae and uh depending on the color of light that was used of course they produced different amounts of oxygen and they were able to kind of d measure the amount of oxygen produced by counting the bacteria or siliates or whatever which gathered around them. Look uh here's an a rotifer. Yeah. So kind of the number of of organisms gathering around it is kind of like a measure on how much oxygen it produces.

[01:01:16]Yeah.

[01:01:18]So um let me see. I'm checking some of this.

[01:01:25]Um so let me see. Uh I no I don't have any channel I sent to all of Okay. Okay.

[01:01:32]Thank you. You sent it. I have to check my email.

[01:01:37]Okay.

[01:01:39]I have to check my email then.

[01:01:42]The 60 times was such an improvement to observing. Thanks for the idea. So it's 20 times. Yeah, this is refers to the following. Many microscopes when you buy them, they come with a 100 times oil immersion objective.

[01:01:54]And um I find it personally not to be I mean I'm using oil immersion obviously but I don't find it quite as as useful as for example a 20 times or 60 times um because the increase in magnification from 60 to 100 is not that big. Uh but you have to have oil and it's messy and and and so on. Yeah.

[01:02:19]Um yes this is actually also quite nice indeed the size comparison.

[01:02:24]Yeah. Um what we have over here is uh I mean cell sizes have quite quite a range difference but you see over here um an amoeba it's a ukareote with a nucleus right the bacteria here proarots. Yeah.

[01:02:40]Um the algae over here also ukarots.

[01:02:42]Maybe you just see the um the size difference of the cells and this kind of makes it much more un and and the rotifer which is made of I don't know around a thousand cells right so um the idea is a little bit the following that um scientists have calculated you've got more bacteria growing on your body and in your body than you have body cells.

[01:03:03]It's kind of difficult to imagine where are all those bacteria. Well, that's only possible because the bacteria are so much smaller.

[01:03:10]Yeah. So, yeah. So, those bacteria are simply so approximately 1/ one,000 of the volume of a ukareotic cell. Yeah. This one over here seems to be a siliate because you can see the tiny little here the cilia on the yeah around it.

[01:03:32]Occasionally, if you're lucky, you also see flagagillates. This here almost this looks like a starch grain from the this is a starch grain from from from the cereal from the wheat.

[01:03:43]And of course uh again here see cinmas are related and uh bacteria swarming around it.

[01:03:58]Yeah, also quite some here is oh look at this here as well they um sometimes you see this happening um after some time uh when the oxygen kind of level kind of drops yeah a few dozen grams yes um you can do it the following a rough estimate you divide your body mass by 1,000 okay um that's a very rough estimate um because yeah if You assume that there are now as probably as many bacteria as you have bacterial cells as you have body cells. And if you estimate that one bacterial cells has 1 1,000th the volume of a body cell because the diameter is approximately 10 times as small. Length time width* height 10 * 10 * 10 makes a 1,000. Um so then basically if you take your body mass and divide it by 1,000 then yeah basically you've got the approximate number of grams of bacteria and if you feel that this is uh if you wonder where do all of the bacteria live well then I will tell you most of them in your intestine.

[01:05:09]So the intestine is actually quite full of of bacteriah here again also very nice uh look this is actually pretty pretty instructive as well. Yeah let me remove this here again. Okay so let's go down with the magnification.

[01:05:28]Maybe we're able to find something else that's interesting.

[01:05:36]Look this one over here.

[01:05:39]Yeah.

[01:05:43]What else is there? Yes. Oh, yes. This is also quite common.

[01:05:49]Very common as well. Let's let's be a little bit patient now. Do you actually see that there is over here um almost like a a road of bacteria and what will normally happen is that they will start to move into one direction together over the course of a couple of minutes. The reason is that they will move towards the edge of the cover glass where there is more oxygen present.

[01:06:18]So they're kind of traveling. Yeah.

[01:06:20]Together. Yeah. Um towards the side. And we can I don't know. I'll put right now it's right in the middle of the um of the micros of the image. Yeah.

[01:06:33]I printed some of your magazines. Yes.

[01:06:35]Okay. Um they follow a gradient. Yes. They follow an oxygen gradient. Um you have to be a little bit patient here. Yeah. I need to talk a little bit about my website which was uh and the forum which was kind of frustrating the last couple of weeks again. Um it was maybe some of you have already realized again it was not accessible. Yeah. Um there were some technical issues u which I got sorted out. Yeah. So just in case you're wondering and uh what is this bacterial line? I don't know. Came up with a term bacterial front like a weather's cold hot front.

[01:07:15]Yeah. So, it's some kind of a Yeah, it would be kind of interesting to to actually come up with a term here. Um, again, this depends uh um you got to be patient to be able to actually see the move and I've made already some some time-lapse videos of this as well. Yeah.

[01:07:32]And you see how the all of those other silates and rotifers and so on kind of diving in there are kind of feeding feed. It's a feeding frenzy.

[01:07:45]Yeah.

[01:07:49]Yeah. Here we go. Here.

[01:07:53]So, the front goes continues over here.

[01:07:57]No, there's quite a bit going on here.

[01:08:00]But is um at the same time I do have to tell you I mean while it's uh um yeah I mean the bacterial concentration is pretty high. Yeah. I mean you um I mean those bacteria are from the water, right? So it would be something different than if you were to grow bacteria that you've isolated from from from a human body or from animals, right? But still you don't know which bacteria they are, right? So you got to be still stick to basic hygienics and yeah um what I'll be doing I'll be rinsing everything properly um later on.

[01:08:30]But um the bacterial concentration is fairly high, right? So just be aware of that. Yeah.

[01:08:36]Ah yeah, some people started to order microscopes.

[01:08:40]Yeah, you got admission for biotechnology. Well, I congratulate.

[01:08:46]Yeah. A little bit about my personal background a little bit. Oh, I love this. Look at this. Um, many of you of course know that I've been now for many years I've been teaching uh biology in high school. sometimes a little bit dry I have to tell you because uh the students have to know the facts and the theory and uh but originally I've got a uh yeah I've got a training as a microbiologist and uh the thing that I found a little bit interesting at that time when I studied microbiology is that it was essentially we did not use microscopes as often as I was hoping to use them because microbiology was actually um yeah mostly a lot of chemistry indeed.

[01:09:28]So um the the fascination with the fascination with uh um with living things um yeah I had to basically maintain that a little bit by becoming active myself and and buying myself a microscope and and doing a little bit of hands-on Yeah.

[01:09:45]activities here. Yeah. Um yeah.

[01:09:50]Yeah. Biology book.

[01:09:53]Yeah. What's the topic that you have to do? you've got tomorrow you've got a test. So what's the chapter?

[01:10:03]Yeah. But um again I think what's something that's really important um is is um something that I think is is really important uh when doing science and so on. science can become very how shall I say dry very quickly and sometimes especially if you're doing laboratory work with biology it's very easy that sometimes you lose a little bit u connection to hands-on biology yeah so I encourage you to not um yeah forget forget about that aspect as well yeah um you can't send it to condense um you um May I say the following. With a Swift 380T, it is possible to center the condenser.

[01:10:52]Um, however, it's um, if it's a little bit off center, but it's not something that you can do dynamically. There are three screws um that you can loosen at the condenser and then you can move it around a little bit. So, the holes are a little bit larger so that you can actually adjust the center and then you can uh, tighten it again. So in that sense you can center it but there is no possibility to dynamically adjust the center of the condenser. So if it's a little bit off center you can actually um yeah at least the model that I have of the 380T um you can actually loosen the screws and make small adjustments.

[01:11:26]It takes some some uh yeah patience however. Yeah. Uh uh why don't you this is an interesting question here. Why don't you teach biology on YouTube like concepts and all? Um, honestly, I've been thinking about that and honestly I've actually made several years ago for my students, I've actually made YouTube videos um, which I occasionally show to students. However, teaching biology on YouTube can be a as videos can be a pretty dry thing. So, it's mostly theory. Basically, I'll be explaining concepts, making drawings.

[01:12:06]Uh, students have to take notes. So, it's not really like so much fun at looking at things, but essentially, I have to explain the structure of a cell membrane, right? And then I have to make drawings. So, it's it's not as quite as as as hands-on. Um, I've been thinking about that for sure because there are lots of biology students out there uh who who would probably need that. Um, but it's probably not um how do you say designed for the masses, right? Um it's biology theory. Yeah.

[01:12:37]Um uh could you briefly recap who's eating who in such a sample? Well, I can very briefly. Let's go down with the magnification to get a better better overview here. Yeah. So, what we're able to see is the following. Let's explain this. Not only who's eating who, but what's actually going on here. So, what you have over here, this here is an air bubble because the slide is slowly drying up. And this basically means that uh those waterers which are actively moving on and which need a lot of oxygen they will of course like they like to be next to the the air right because the oxygen diffuses into the water and then they have of oxygen here over here. What you see over here is is um you see uh those bacteria the bacterial front as we call it and it also moves towards the oxygen right. Um however um those bacteria bacteria are actually being eaten by the rotifers as well. So what we have is we have actually a a small food chain. Those little white dots that you see here these might be some of the starch grains from the uh from from the wheat that I added as a food. Um the bacteria eat the starch. Um, and then the ciliates and the rotifers will eat the bacteria. And those rotifers here are not single-sellled. They're actually microanimals. They're real animals. So they um are multisellular animals. Yeah.

[01:14:03]Um and uh yeah actually one of the smallest animals that they are and uh they are also to be known to be so-called utellic and utelic means that uh the number of cells that they have is fixed. For example, humans are not utelic. Humans different human beings have different number of cells. If you're larger, you have more cells. If you're smaller, you have fewer cells obviously, right? Um but with those rotifers and other micro animals also for example um tardigrades they're utelligan this basically means that it's possible and scientists have done that to trace every individual cell back to the first original cell. Yeah. And they're all female. That's also correct.

[01:14:45]And this caused a big headache to some scientists. How can they survive if they are all female? What about the genetic variability, the genetic diversity? Why are they able to survive? Because you need actually normally in the quotation marks you need a fertilization to happen to increase genetic variability diversity. So they're kind of wondering scientists were wondering how is it possible if they're genetically all the same because they've are born by so-called parthononogenesis which means that they lay eggs but they're not fertilized. It's a form of asexual reproduction. So if they're genetically the same, how are they able to survive if the environment changes?

[01:15:26]Right. A big mystery because um actually they found a solution. Um it's kind of obvious. What they do is they do horizontal gene transfer. This means is that they have a method somehow to exchange DNA directly with each other to increase the genetics variability. Yeah.

[01:15:43]Yeah. Um Um Yeah, I get it. I get it. Yeah. Is recentering. I get it. Is not practical.

[01:15:52]Yeah. Um, however, the good news uh is is um you you don't lose a huge amount of image quality if it's not in the center. Yeah.

[01:16:02]Yeah. Um I feel kind of sad killing rotifers when trying to make slides and I I know what you're talking about and I get it. However, um yeah, those animals, as far as we know, they don't have a consciousness because they don't have a fully developed brain. Yeah. Yeah. Uh the Yes.

[01:16:28]The dark field effect. I get it. Yeah.

[01:16:32]Yeah.

[01:16:33]Yeah. So, look, this is a real feeding frenzy going on here. Or oxygen. Yeah. Yeah.

[01:16:42]So, kind of means that sometimes it's not necessary to slow them down because there's so many of them actually together that it's possible to directly observe them. Yeah. So, let's look I'm going to put the DIC away. Uh no, that's what No, that's wrong. Uh this one here.

[01:17:01]That's not bright field.

[01:17:05]Yeah. Fascinating. I mean, I don't know.

[01:17:07]I've been doing this for Yeah. for so many years. I'm still always fascinated by this. Yeah.

[01:17:14]Yeah.

[01:17:18]Yeah. Exactly. I'm reading again.

[01:17:23]Yes. That's another thing here. I use Google Photos generally. That's something I I recommend in any case that um uh you can significantly improve and maybe that's the biggest improvement is you just do a con a contrast improvement of whatever. Yeah. micro uh photo microraph you've got. If you do a contrast improvement then subjectively the image will also appear to be more crisp and sharp. Yeah. Um what time is it? Yeah, it's 1 minute and 7 1 hour and 17. Yeah, I think I'm just going to slowly call it a day again, right? Um yeah and uh I have actually read on Reddit today a new slide preparation technique that I would like to experiment with um and that is is how it's possible and somebody posted actually nice image on Reddit in the microscopy um subreddit um is is is how to actually make crosssections of hair and fibers um to make them visible.

[01:18:25]That's also something I would like to to try. Yeah. Um ah yeah. Any plans to check on one of the Discord servers?

[01:18:33]Yeah. Uh I will I will check uh because I was very busy the last couple of weeks because uh end of school but now the holidays started luckily so I have a little bit more time. Okay. Yeah.

[01:18:50]Yeah. Exactly. So I would like to try that method as well to u um to prepare a slide where you're able to look at the bristles or adhere being vertical from the top. Yeah. So it's it's very difficult actually to to look at that.

[01:19:06]Um but uh there is a technique how to do that and I would like to experiment with that. Yeah. So maybe maybe Yeah. Uh this is uh something I'm going to try. Do they need sleep? Probably not I would say.

[01:19:20]Yeah. Um I mean I I'm quite sure that they must have some kind of a resting uh phase as well but whether they really sleep. Yeah. Okay. Um yeah. So what I'm going to do now is I'm just going to call it a day again or an evening rather because it's already quite late at night of where I am. See? Um, and I think I'm just going to, yeah, wish you all the best and uh, happy microbe hunting and hope that as always that uh, those microscopy sessions also motivate you a little bit to pick up a microscope. Of course, uh, there is always something to discover. Please feel free, of course, to post something in the comments. Yeah, hope I was able to respond to all of the questions and um yeah, and uh hope to see you again next week. And if for whatever reason something unexpected arrives and I'm not able to do the live stream, please check the community posts. I will uh try to activate them a little bit more as well to be in contact with you in case there is some some announcements here. Um okay. Um all the best and uh yeah, I will check my emails. Okay. Uh happy micro hunting and hope to see you next week. Bye-bye.