1.
Anal Biochem
; 219(2): 356-9, 1994 Jun.
Article
in English
| MEDLINE
| ID: mdl-8080092
ABSTRACT
A modified version of the Lowry protocol for protein measurement is being introduced in which the increment in color due to copper-protein interactions can be directly equated to the concentration of peptide groups (the CO-NH moieties) present in the sample. The method provides an accurate estimation of protein concentrations in the range of 5-40 micrograms, with a sensitivity similar to that of the original assay procedure. It yields hardly any protein-to-protein variation with simple proteins and eliminates the interference by four compounds that commonly affect the Lowry assay. A numerical factor has been calculated that allows conversion of micromoles of peptide groups into actual micrograms of protein present in the sample.