Applicability of Coomassie brilliant blue G-250 as the staining dye for paper and cellulose acetete electrophoretic analysis of serum proteins

Abstract

The staining ability of 5 dyes was compared by staining a known amount of human serum albumin spotted on a sheet of Separax, eluting the protein-bound dye, and measuring absorbancy at respective peak wave lengths. The relative color intensity of G-250 was much higher than that of R-250, Ponceau 3R, Amidoblack 10B or Procion blue. The colorimetric value of G-250 binding to serum protein fractions considerably fluctuated because of an unavoidable inaccuracy of spotting of the protein solution onto Separax. However, the relative proportion of protein fractions (expressed in percentage) showed a reasonable variation, especially when serum was diluted 5-fold with saline. The similar tendency was obtained when the stained protein fractions were measured using densitometer. A few examples of the G-250 staining method applied to paper electrophoresis of cerebrospinal fluid and urinary proteins were presented.