Encyclopedia of Biophysics

Living Edition
| Editors: Gordon Roberts, Anthony Watts, European Biophysical Societies

Protein Concentration Determination Using Dyes and Beer-Lambert Law

  • Alison RodgerEmail author
Living reference work entry
DOI: https://doi.org/10.1007/978-3-642-35943-9_774-1



Although proteins have different percentages of different amino acids, each residue has an amide bond linking it to the next residue in the chain. A number of concentration determination methods have been developed that involve derivatizing the amides with a dye and spectroscopically determining the concentration of the derivatives (Noble and Bailey 2009). The three methods mentioned below all rely on a standard of known concentration to enable a calibration curve to be plotted. The calibration is not necessarily linear and ideally is the same protein of known purity since the dye-binding efficiency varies from protein to protein. Other reagents in the sample such as buffer salts and detergents may also interfere with either the chemistry or the spectroscopy of the dyes.

Basic Characteristics

The methods for three commonly used assays are outlined below.

Biuret Method

The biuret method is simple and reasonably specific as...

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  1. Bradford MM (1976) Rapid and sensitive method for the quantitation of microgram quantities of protein utilizing the principle of protein-dye binding. Anal Biochem 72:248–254CrossRefGoogle Scholar
  2. Noble JE, Bailey MJA (2009) Quantitation of protein. Methods Enzymol 463:73–95CrossRefPubMedGoogle Scholar

Copyright information

© European Biophysical Societies' Association (EBSA) 2018

Authors and Affiliations

  1. 1.Department of Molecular SciencesMacquarie UniversityMacquarie ParkAustralia

Section editors and affiliations

  • Alison Rodger
    • 1
  1. 1.Department of Molecular Sciences, Macquarie UniversityNWSAustralia