2001 年 45 巻 1 号 p. 75-81
Several dyes were evaluated for their potential use as indices of ionic boundaries and pH discontinuities during polyacrylamide gel electrophoresis (PAGE). Dye selection was based largely upon color transition over the pH intervals present in the commonly used Tris-HCl-glycine buffer systems. In the absence of sodium dodecylsulfate (SDS) nitrazine yellow, cresol purple, cresol red, and phenol red had relative mobilities (relative to the chloride boundary; RC1) of 1.00 at 20% polyacrylamide concentration (% T) compared to bromophenol blue (BPB) for which RC1=0.77. The homologue of BPB, 3, 4, 5, 6-tetrabromophenolsulfonephthalein (TBPS), exhibited a useful color transition over the pH 6.6-8.2 range but was an equally poor indicator of the chloride boundary at 20% T in the absence of SDS (RC1=0.73). The RC1 of other dyes was increased in the presence of SDS, particularly the cationic dye neutral red which complexes with micellar but not monomeric SDS. In the presence of SDS, all dyes except neutral red exhibited RC1 of 1.00 at 15% T, whereas only neutral red and nitrazine yellow had RC1 values of 1.00 at lower gel concentrations. Partial characterization of SDS, in terms of RC1 and zone broadening, was performed in a system devoid of extraneous SDS in the gel or electrolytes.
