Should the biuret reagent be prepared and used at the ready?

Want. The biuret reagent is composed of two reagents, biuret A (NaOH) and biuret B (CUSO4) (the composition of biuret reagent A is an aqueous solution with a mass fraction of sodium hydroxide g ml, and the component of biuret reagent B is an aqueous solution with a mass fraction of g ml of copper sulfate), and the biuret reagent can verify the presence of proteins.

Here's how:

First, biuret reagent A was added to the tissue sample solution with uniform shaking (an alkaline environment must be created), and then biuret reagent B was added with uniform shaking. If the tissue contains protein, you will see the solution turn purple. Compounds with two or more peptide bonds can react purple with biuret reagents.

The peptide bond of the protein can be complexed with Cu2+ in an alkaline solution to form a purplish-red complex. The shade of color is directly proportional to the protein concentration.

NH2ConHCn2 is a product obtained by two molecules of urea heated at about 180 degrees Celsius to release one molecule of ammonia.

The biuret reagent is originally used to detect biurea, because there is also a -conh-group in the protein can also be used to test the protein, and the color is purple after contact with the protein.

When using the biuret reagent, it must be noted that g ml of sodium hydroxide solution must be added first, followed by g ml of copper sulfate in water. (If copper sulfate [CuSO4] solution is added first, and then sodium hydroxide [NaOH] solution is added, the alkaline environment cannot be fully created, and CuSO4 will metacompose with NaOH to form blue copper hydroxide [Cu(OH)2] precipitation, resulting in unclear phenomena and unable to achieve the experimental purpose well.) )

Good luck with your studies!

Yes, think about how it is configured, and you should understand why you want to use it.

Biuret reagent A is a sodium hydroxide solution, and biuret reagent B is a copper sulfate solution.

The methyl solution of the Filin reagent is a NAOH solution per ml.

Solution B is a CuSO4 solution per ml.

Liquid A of the biuret reagent is a NaOH solution per ml.

Liquid B is per ml of Cuso solution.

Feilin reagent is to detect reducing sugar, it is necessary to mix liquid A and liquid B in the same proportion, shake well, do not let the precipitate sink at the bottom of the test tube, and then add it to the reducing sugar, and the brick-red precipitate will appear when heated in a water bath for 5-6min.

Biuret reagent.

It is used to detect biuret, because the protein molecule contains many peptide bonds similar to the structure of biuret, so it can also react with copper ions in alkaline solution. When the substrate contains peptide bonds, the copper in the test solution is coordinated with the polypeptide, and the complex is purple. Concentrations can be analyzed colorimetrically, with a wavelength of 540 nm in the UV-Vis spectrum.

The sensitivity of the identification reaction is 5-160 mg ml.

1. The role is different

Fillin's reagent is a newly formulated solution that reacts with an aldehyde group under heating conditions and is reduced to a brick-red precipitate that can be used to identify the presence of soluble reducing sugars.

When identifying whether a protein is present in a biological tissue, the biuret method is commonly used, using a biuret reagent, and a biuret reaction occurs. The diuret reaction is essentially a purple reaction with the biuret reagent in an alkaline environment. The protein molecule contains many peptide bonds that are similar to the structure of biuret, so the protein can have a color reaction with the biuret reagent.

2. Different ways to use

Feilin reagent is used immediately after the equal amount of liquid A and B are mixed, and when using biuret reagent, 1ml of solution A should be added first, shake well, and then add 4 drops of solution B, shake well, and then observe the experimental phenomenon.

3. The composition is different

Although Filin reagent and biuret reagent are both formulated with NaOH and CUS04, the dosage is still different. Feilin reagent is divided into two types: solution A and solution B, of which solution A is NaOH solution, and solution B is 0 05g ml of CUS04 solution. The biuret reagent is divided into liquid A and liquid, of which liquid A is NaOH solution and liquid B is CUS04 solution.

Precautions: When using biuret reagent, it must be noted that g ml of sodium hydroxide solution must be added first, and then g ml of aqueous solution of copper sulfate. (If copper sulfate [CuSO4] solution is added first, and then sodium hydroxide [NaOH] solution is added, the alkaline environment cannot be fully created, and CuSO4 will metacompose with NaOH to form blue copper hydroxide [Cu(OH)2] precipitation, resulting in unclear phenomena and unable to achieve the experimental purpose well.)

The biuret reagent is composed of liquid A (sodium hydroxide solution by mass) and liquid B (copper sulfate solution by mass).

For the identification of proteins, it is necessary to add solution A before adding solution B, and the amount of solution B added should be small.

The substance is different, and the diuret reagent A solution is an aqueous solution of NaOH. Diuret B solution is an aqueous solution of CuSO4.

The difference between the two: the mass fraction of solution A of diuret reagent is g ml at different concentrations. The mass fraction of solution B of biuret reagent was g ml.

In order to create an alkaline environment, the amount of diuret reagent A is generally 3 ml. The purpose of diuret reagent B solution is to make the peptide bond of the protein complex with Cu2+ complex in alkaline solution. The shade of color is directly proportional to the protein concentration.

Add a smaller amount, just a few drops.

Note: When using biuret reagent, add g ml of sodium hydroxide solution first, and then add g ml of copper sulfate in aqueous solution. If copper sulfate solution is added first, and then sodium hydroxide NaOH solution is added, the alkaline environment cannot be fully created.

Diuret is a chemical substance, and the two reagents used to detect proteins are called biuret reagents because the detection principle is similar to the formation of biuret.

The above content refers to: Encyclopedia-biuret reagent.

Biuret reagent. A YesSodium hydroxidesolution, biuret reagent B is a copper solution of sulfur code cokulate. Confusion

Biuret reagent is an analytical chemical reagent used to identify proteins.

It is an alkaline copper-containing test solution that is blue in color and consists of sodium hydroxide or potassium hydroxide.

Formulated with copper sulfate and potassium sodium tartrate, it appears purple when it encounters proteins.

Biuret reagent A is the mass fraction of sodium hydroxide.

is g ml of aqueous solution, and the mass fraction of copper sulfate of biuret reagent B is g ml of aqueous solution.

First, add 3ml of biuret reagent A to 3ml of tissue sample solution with uniform shaking (alkaline environment must be created), and then add 1 2 drops of biuret reagent B with uniform shaking. If the tissue contains protein, you will see the solution turn purple. Has two or more peptide bonds.

can produce violet cluster color reaction with biuret reagent.

The peptide bond of the protein can be complexed with Cu2+ in an alkaline solution to form a purple complex.

The shade of color is directly proportional to the protein concentration.

The above content refers to: Encyclopedia-biuret reagent.

Because if liquid A and liquid B are added together at the same time, there will be reactions between them, which will affect the effect of the experiment, so it is better to add them separately.

Liquid A is added first to provide an alkaline environment, and the protein contains aldehyde groups, together with freshly made copper hydroxide.

A redox reaction occurs.

The resulting copper peroxide can only exist in an alkaline environment, and because the copper peroxide is brick-red precipitate, it will appear purple when combined with blue copper ions.