Determination of the reaction product of glutaraldehyde and amine based on the binding ability of coomassie brilliant blue

Abstract

Coomassie Brilliant Blue G-250 (CBBG) was bound to the reaction products of glutaraldehyde with various compounds containing amino group. The reaction products of acetaldehyde and malonaldehyde with the amines did not bind with CBBG, indicating that the binding was specific for the product of glutaraldehyde. The dye binding products rapidly formed in alkaline pH. Gel filtration chromatography indicated that a reaction product of more than 2 kDa has a dye-binding ability. The reaction product of glutaraldehyde with 6-aminohexanoic acid was separated with SP-Sephadex. CBBG was bound to the first eluted fraction from the column with highest affinity. The absorbance at 595 nm by CBBG binding was linearly related to this lyophilized fraction at a concentration of up to 250 μg/ml, suggesting its applicability to the determination of the reaction product of glutaraldehyde and amine. The present method should contribute to our understanding of the chemistry of glutaraldehyde associated with diverse fields, such as enzyme technology and biochemistry.