Biuret's Test - Qualitative Test in Proteins


"Biuret_Test_2" courtesy of Ozone aurora. cc by

Some structural unit's characteristic of particular proteins enables these proteins to undergo various colour reactions with some reagents. We depend on these colour reactions to identify such proteins. The Biuret's test procedure is presented in this programme.


This video lesson demonstrates the laboratory procedure in Biuret's test. At the end of the lesson, students should be able to describe the test and its positive results, understand the basic principle and write a balanced equation for the test.

Author(s): George KoffuorView Details of Author
Year: 2012
Keywords: biuret's test, proteins, peptides, amino-acids, qualitative test
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cc-by-nc© 2012, KNUST

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Biuret's test for peptide bonds is a reaction characterised by a violet colour upon the addition of copper sulphate to all compounds with two amide or peptide bonds linked directly or through an intermediate carbon atom. It is used in the detection and estimation of proteins and peptides having more than two amino-acids.

A pink to purple/violet colour indicates the presence of proteins. A more intense coloration indicates the presence of more complex proteins.




Write a balanced equation for Biuret's Test

Understand the principle behind Biuret's Test.


Lesson Content


Biuret's Test (video)
Biuret's Test







Dr. George Koffuor
Department of Pharmacology
College of Health Sciences - KNUST
Kumasi, Ghana

Student Volunteer

Stephen Fletchyann
Department of Communication Design
Kumasi, Ghana


OER Technical Support




Benjamin Prempeh
OER Media Specialist
KNUST, Kumasi - Ghana

John Kofi Dogbey
Media Specialist
KNUST,Kumasi - Ghana

Voice Over

ella kasanga

Ella Kasanga
Kumasi, Ghana




This programme was produced with support from the following: