D- 332 | Test for Proteins- Biochemistry | Rapid revision notes #Pharmacology

Added: 2026-05-30

[00:00:00]Hello dear students, welcome back to the GDC classes. So dear students, welcome all of you once again to the GDC Digestor series. And in today's digest series, we are going to talk about tests for the proteins, that is, what are the tests for proteins.

[00:00:18]What chemical agent is used in those tests? And what is the identification of that test and what conclusion do we get from it?

[00:00:27]You will get the summary of all these important things in this video. So are you all ready for this digester series?

[00:00:36]That is the test for the protein under the biochemistry subject. So let's get started. The first question that comes up is how many tests are there? We forget the times. So, if we make a small trick by which we can remember all the tests at once, will it be okay? So here we created Big Funny Hippos Hug My Mishy New Pet. So whatever you write two-three times, it will become soft and smart automatically. What does it mean? First came Big. And big here means sir by urate test comes. Funny will make a fallen catch, our taste will come. Heller test from Hippos.

[00:01:12]Hopkin Cole reaction from Hug. Ma se Milan test Miss se Mollis test New se Ninhydron test Pet se Pavlis test So se Sakaguchi test Soft se Sen test Smart se Sulphur test and Jojo se Xanthoproteic test come to us. Now if you see, what is our total here, sir? Here we have total 12 tests in which one? Only in the identification of proteins. We won't just talk about protein. Both protein and amino acids will be discussed. Now what are the things in it? Let us try to understand them one by one.

[00:01:47]But please say it again.

[00:01:49]Big funny hipo hug my miss new pet so soft and smart jojo. It is simple. Just practice two-three times and you will learn it. Now let's see one by one. So first comes our test which we name Biuret test. Now Biuret Test is one of the questions asked to you many times in different exams.

[00:02:09]What reagent is used in the Biuret test? So sir, here it is basic because potassium hydroxide, so potassium hydroxide with the hydrated copper sulphate by uret test, copper sulphate and sodium potassium sulphate, copper sulphate sodium potassium sulphate, both of these are reacted in the presence of potassium hydroxide from the sample and there comes a purple colour due to the formation of the copper coordination complex, so it identifies that yes there is the peptide bond linkage present in this sample. From that we do not know which one is which, what is it. The only thing that can be detected by the Biuret test is that in the sample there is the peptide bond present. So it became known that peptide bond is present in it. Ok? Now let's move ahead. Next comes our test, That Is Called As Funny. It is funny that we have our Folin sequel test in which we will react in the presence of tungstate and sodium tungstate and sodium molybdate i.e. tungsten and molybdenum sodium and after doing calorimetry there it becomes known that sir what is present here is phenolic group i.e. tyrosine so if tyrosine amino acid is present then here we will tell for which identification it is called Folin test, next comes our Hippo i.e. HH for Heller test, we will talk about it.

[00:03:39]In Heller test, we react the sample with nitric acid and if white precipitate is formed after reacting with nitric acid then it confirms that there is coagulation and coagulation will show you the presence of albumin in the biological fluid including urine.

[00:03:57]So that's what we'll talk about: the Heller test. Next we will talk about Hopkin Cole reaction and what does the sample react with in Hopkin Cole reaction?

[00:04:08]Glycolic acid. And if violet or purple color appears that will indicate the presence of tryptophan. So we said that if the phenolic group i.e. tyrosine is present then that is our Folin Calculation Test. And what is the Hopkin test for? To describe the indole ring. That means tryptophan group amino acid is present here. The next test is the Milan test which has been asked many times.

[00:04:34]What happens in the Milan test? In this, the mixture is reacted with sulfuric acid and mercury sulfate in the presence of sodium nitrite.

[00:04:44]And if red color appears then what does it indicate there? There is the phenolic presence of the yes tyrosine. So remember both Milan and Fallin. What are both Milan and Fallin for? Tyrosine is for.

[00:04:57]What does the Hopkin cold test for?

[00:04:59]Tryptophan stands for amino acid i.e. andole group.

[00:05:01]Next comes our Mollis test. Now you know about Molis reagent or Molis test where we react naphthol, alpha naphthol with the ethanol. This is the identification of carbohydrates. But if the peptide bond is present from biuret. And after that it is found that the Mollis test is also coming positive. That means it's a glycoprotein. That means carbohydrates are present there along with proteins. If red purple color comes then. So the Mollis test in the protein shows the glyco protein. Please write the Milan test separately.

[00:05:37]Who is our Milan test for? Both the Millon and Folin tests are for tyrosine.

[00:05:42]While we said what is the Hopkin cold test for? is for tryptophan. What does the bi urate test for? Ours stands for peptide linkage. We cleared this major here.

[00:05:51]Now let's move ahead. Ninhydron Test You must have read that Ninhydron test is used for the detection of the alpha amino acid. Because what are the major amino acids in our body? Contains alpha amino acids. And to identify that same alpha amino acid, our ninhydron reagent which contains two two dihydroxy indane one three dione two two dihydroxy indane one three dione reacts with the sample. If there is a purple blue and pink purple color complex, which we also call Ramen Purple.

[00:06:28]So he says that the test must have been done by adding ninhydr reagent. It tells us there is the presence of the alpha amino acid in the sample. Next Paulis test. Pauli's test is for identifying the imidazole ring containing structure. And imizole containing ring amino acid is our only one.

[00:06:48]That is the histidine that will be discussed.

[00:06:50]Now what is the reagent in this? The dye is azotized sulfenic acid. And if after reacting with the sample there is a red color that shows yes that has the imidazole ring that is the histidine.

[00:07:04]Next Sakaguchi test well known Sakaguchi test for the our here is for guanylate guanidine group i.e. Arginine Sakaguchi test G remember Arginine Sakaguchi Arginine Sakaguchi Arginine here we use alpha naphthol and sodium hypochlorite. Red color comes. The presence of arginine and arnine will be discussed. It is the only amino acid where our guanylate indino group is present. What is the Sanger test for, sir? For sequencing of amino acids.

[00:07:36]What is Sanger reagent and Sanger reagent? Name has been asked. One fluoro two 4 di nitro benzene will be discussed.

[00:07:44]Sanger test for the amino acid sequencing. And it is not just Sengar that we will also talk about. But before that we will talk about sulfur test sulfur dioxide. Meaning it will react with sulphur dioxide and this tells about the sulphhedral group. And what are the sulfur containing amino acids?

[00:07:59]Although there is cysteine ​​and methionine, but methionine will not be present here. Here we will talk about cysteine ​​and cystine. Not for the methonine. Sir, why so? Because Sir Methionine is not sulfur free. It is sulphur free here. Therefore, this sulfur test does not give positive methionine. Cysteine ​​gives us positive. Xanthoproteic test that is for the concentration. There we use concentrated nitric oxide and the yellow precipitate indicates aromatic amino acids. So for aromatic amino acids, for arginine, for imdazole ring containing amino acids and for alpha amino acids and for sulfur containing amino acids, we talked about different tests for each class.

[00:08:41]Now please summarize these and write down which tests are there and for what purpose they are done. Let's look at its questions, it will be more fun.

[00:08:50]First of all ninhydron is used what is ninhydron for sir? For alpha amino acids, we have a ninhydron test for detection.

[00:08:58]An amino acid which gives a yellow precipitate in the xanthoproteic reaction. and xanthoproteic reactions i.e. aromatic amino acids. Now what do you see here in aromatic amino acids? Is tyrosine visible? We put tyrosine, phenyl alanine, tryptophan, histidine. We change these randomly according to the option. Primary test for the amino acids. Now if the primary test of amino acid is asked then what is it? of amino acids. So sir, obviously how is alpha amino acid identified? By the ninhydron test. All the following are tests for the amino acid exception. Just take a look here. Everything will be found. It is biuret, union, xanthoprotic. But the Moll's test is not for certain amino acids. This is for identification of carbohydrates.

[00:09:45]Alpha Amino Acids React With Ninhydron To Give The Color Complex.

[00:09:50]Alpha amino acids react with ninhydron.

[00:09:53]And what kind of colour comes after reacting with ninhydrin? Sir, do you get a little bit of our pink type color? We just talked about color.

[00:10:00]For the determination of amino acid sequence of protein is used.

[00:10:06]What is the use of sequencing of amino acids? Sanger reagents are used. Yes sir. Sequencing will be done only with Sanger reagent. The Heller test is used for the detection of the condition just discussed. Heller test used for the detection of protein urea. That means how much urine are we passing?

[00:10:25]How much protein is going into the urine? Our detection test for that is the Heller test. The specific test for the identification of the ring of amino acid, what was the specific test for Folin, sir, we talked about tyrosine, we talked about Milan test, ours is different, sir, we talked about tryptophan, we talked about biuret test, we talked about peptide ring, but we will talk about Pavlis test, yes sir, this is for the specific ring, our biuret test confirms the presence of peptide bond, it gives confirmation of peptide bond, identification test for the protein. Now what is the identification test for protein? That sir, peptide bond is present in it.

[00:11:05]That means if our biuret test is coming positive then it will tell that yes, there is protein here. Niha for amino acid is nitrine. But there is biuret for protein.

[00:11:15]Because the pressure of the peptide bond is detected. Milan test is positive for whom will he come sir? Tyrosine. This is what we just wrote about, the Milan test for the tyrosine. General Test to Identify the Carbohydrate. Now what better identification test for carbohydrates than the Molisch test? Which of the following is the taste for the protein? Now there is also protein biuret and both xanthoproteic reactions.

[00:11:40]We will know from both. Just one tells us that there is a peptide bond. One tells us that there is an aromatic amino acid.

[00:11:47]So here is our cute little topic that is the test for the identification of the protein and amino acids.

[00:11:55]Please give your love and feedback on how you liked this digester series. If you are enjoying it then please leave your comment. We will meet you in the next video with some new content. Until then, keep learning with the GDC. Thank you so much to all. Thank you everyone.