Freimoser:Protocols:ProteinQuantification

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Source

The quantification methods listed below represent those that we find most useful. The descriptions are part of a more detailed list of protein quantification methods [1]
General Reference: Stoscheck, CM. Quantitation of Protein. Methods in Enzymology 182: 50-69 (1990). [2]

Absorbance assays

Absorbance at 280 nm

• Range: 20 μg to 3 mg
• Volume: Depends on cuvette - volumes range from 200 microliters to 3 ml or greater
• Accuracy: Fair
• Convenience: Excellent, if equipment available
• Major interfering agents: Detergents, nucleic acids, particulates, lipid droplets

Absorbance at 205 nm

• Range: Roughly 1 to 100 μg
• Volume: Depends on cuvette - volumes range from 200 microliters to 3 ml or greater
• Accuracy: Fair
• Convenience: Very good
• Major interfering agents: Detergents, nucleic acids, particulates, lipid droplets

Colorimetric assays

Modified Lowry

• Range: 2 to 100 μg
• Volume: 1 ml (scale up for larger cuvettes)
• Accuracy: Good
• Convenience: Fair
• Major interfering agents: Strong acids, ammonium sulfate

Bradford assay

• Range: 1 to 20 μg (micro assay); 20 to 200 μg (macro assay)
• Volume: 1 ml (micro); 5.5 ml (macro)
• Accuracy: Good
• Convenience: Excellent
• Major interfering agents: None