ALBUMIN STANDARDS AND THE MEASUREMENT OF SERUM-ALBUMIN WITH BROMCRESOL GREEN

A rapid and reliable method for measuring serum albumin employing brom cresol green is described. The addition of albumin to a solution of br omcresol green in a 0.075 M succinate buffer pH 4.20 results in an inc rease in absorbance at 628 nm. The absorbance-concentration relationsh ip is linear for samples containing up to 6 g/dl albumin. Bilirubin, m oderate lipemia, and salicylate do not interfere with the analysis. Th e use of a nonionic surfactant (Brij-35) reduces the absorbance of the blank, prevents turbidity and provides linearity. The results by this method agree very well with those obtained by electrophoresis and sal t fractionation. The method is simple, it has excellent precision and the reagents are stable. A protein standard is introduced which can be employed for both the total serum proteins and albumin determinations .