[Rapid and sensitive micromethod for protein determination by the Coomassie-blue technique]

The Coomassie blue method of proteins quantitation initially reported by Bradford and modified by Macart et al. appears to be simple, fast, sensitive and of low cost. In this study, we report an improved micromethod derived from the technic described by Macart. Applied to the protein quantitation of 100 cerebrospinal fluid (CSF) specimens and 50 serum specimens our method showed a very good correlation with the macromethod of Macart (r = 0.985 for CSF proteins, r = 0.944 for serum proteins) and also with the Lowry technic (r = 0.986 for CSF proteins, r = 0.898 for serum proteins). Our technic may be used with various biological fluids (urines, tears, saliva...) and seems to be of particular interest for low protein level fluids and for little volume samples (it needs only 20 mcl).