Table of Contents
What is in biuret reagent?
A biuret reagent may be used to test the aqueous sample. This blue reagent is made by combining sodium hydroxide and copper sulfate solutions. A few drops of this reagent will turn the aqueous sample containing compounds with peptide bonds from pale to intense violet colour.
How does the biuret reagent react with proteins?
Proteins can be detected through the use of the Biuret test. Specifically, peptide bonds (C-N bonds) in proteins complex with Cu2+ in Biuret reagent and produce a violet color. A Cu2+ must complex with four to six peptide bonds to produce a color; therefore, free amino acids do not positively react.
What is the meaning of biuret solution?
: a chemical reaction that produces a violet or purple color when biuret or most proteins are exposed to a reagent of copper sulfate in alkaline solution.
How does Biuret reagent work?
The biuret test measures peptide bonds in a sample. In an alkaline solution, copper II is able to form a complex with the peptide bonds. Once this complex has been formed, the solution turns from a blue color to a purple color. The deeper the purple color, the more peptide-copper complexes that have been formed.
Why is it called Biuret reagent?
Biuret is a compound formed by heating urea at 1800 which results in the condensation of 2 molecules of urea. The peptide bonds in Biuret give a positive result for the test hence the reagent is named so. It is considered as a general test for compounds (proteins and peptides) having two or more peptide (CO-NH) bonds.
How is Biuret reagent prepared in the lab?
Biuret reagent is prepared by adding NaOH in CuSO4 solution, making it alkaline. Mix both the solution in volumetric flask and make it final volume to 1000 ml by adding distilled water.
How can we test for protein?
Proteins are detected using Biuret reagent . This turns a mauve or purple colour when mixed with protein.
What reagent is used for protein testing?
Biuret reagent A tri- or tetra-dentate chelation with the peptide nitrogen produces the characteristic color. This is found with dipeptides. The reagent is commonly used in the biuret protein assay, a colorimetric test used to determine protein concentration by UV/VIS spectroscopy at wavelength 540 nm.
How is biuret reagent prepared in the lab?
How does biuret reagent work?
Why is BSA used in Biuret test?
An aqueous solution of bovine serum albumin (BSA) is commonly used as a standard in testing because of its stability in testing, low cost, and is readily available as a byproduct from bovine blood.