Explain Methods of Protein Estimation?

Several methods for protein estimation are available. These methods are based on several analytical characteristics of the protein. Laboratory estimation of protein is based on any of the following principles:

i) Nitrogen estimation based on the principle of Kjeldahl's method,

ii) Estimation of tyrosine in protein (as in Lowry's method) or both phenyl alanine and tyrosine in protein (Folin's method).

iii) Biuret method - most commonly used method in clinical practice and teaching laboratories.

We have studied some of the tests in qualitative methods and the principle is the same. The Biuret method for example can be used for both qualitative and quantitative estimation of proteins. Let us learn about these methods in details. We shall, however, focus on the kjeldahl's method and the biuret method here in this section.