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).
Absorbance assays
Absorbance at 280 nm
- Range: 20 micrograms 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 micrograms
- 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 micrograms
- 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 micrograms (micro assay); 20 to 200micrograms (macro assay)
- Volume: 1 ml (micro); 5.5 ml (macro)
- Accuracy: Good
- Convenience: Excellent
- Major interfering agents: None
