Protein Quantitation Concentration Protocols

Absorbance assay at 280 nm.  This method is just as convenient as for absorbance at 280 nm.  It may be preferred if there is excessive contamination by nucleic acids, since nucleic acids absorb very little radiation at 205 nm.  Setting the wavelength is a bit tricky since 205 nm is right on the shoulder of the protein peak. - [Read Absorbance Assay 205 nm]

Absorbance assays are fast and convenient, since no additional reagents or incubations are required.  No protein standard need be prepared.  The assay does not consume the protein.  The relationship of absorbance to protein concentration is linear.  Because different proteins and nucleic acids have widely varying absorption characteristics there may be considerable error, especially for unknowns or protein mixtures. - [Read Absorbance Assay 280 nm]

Biuret Protein Assay. Includes Materials, methods and procedure. - [Read Biuret Protein Assay]

A Comparision of Different Protein Determination Methods and protocols in table format. The Wolfson Centre for Applied Structural Biology The Hebrew University of Jerusalem Dr. Mario Lebendiker. - [Read Comparison Different Protein Quantitation Determination Methods]

Determination of the Extinction Coefficient for a Protein of Unknown Concentration. The concentration can be determined for a solution of a pure protein with unknown extinction coefficient. - [Read Determination of the Extinction Coefficient for a Protein of Unknown Concentration]

Find a list of assays for the determination of protein concentration in a solution.  This list includes the sensitivity range, volume/amount of sample needed, subjective comments on accuracy and convenience, and major interfering agents.  Procedural details, equipment requirements, and references are outlined in the individual assay documents. - [Read List of Protein Assays]

Phosphoamino acid analysis of non-TCA precipitable proteins and Alkali treatment of gels protocols. Woodgett Lab. - [Read Phosphoamino acid analysis of non-TCA precipitable proteins]

TCA Protein concentration of Laemmli gel samples. Woodgett Lab. - [Read TCA Protein concentration of Laemmli gel samples]

UV Absorbance 280 nm Protein Determination. Simple and quick method to accurately quantitate total protein in purified material or approximately quantitate total protein in crude lysates or partial purified material. Quantitation of the amount of protein in a solution is possible in a simple spectrometer.  Absorption of radiation in the near UV by proteins depends on the Tyr and Trp content (and to a very small extent on the amount of Phe and disulfide bonds).  Dr. Mario Lebendiker - [Read UV Absorbance 280 nm Protein Determination]