Electroanalytical determination of a reactive dye currently used in affinity chromatography for protein purificaton

Abstract

ELECTROANALYTICAL DETERMINATION OF A REACTIVE DYE CURRENTLY USED IN AFFINITY CHROMATOGRAPHY FOR PROTEIN PURIFICATON. Procion Green HE-4BD is a reactive dye currently used in affinity purification, and commonly present as a contaminant in the final biological preparation. An assay method is described to determine trace amounts of the dye in the presence of human serum albumin(HSA) and leakage from agarose as affinity sorbent by cathodic stripping voltammetry. The proposed method is based on the reductive peak at -0.55V in B-R buffer pH 3 (E=0V and t=240s), obtained when samples of HSA 2% (m/v) containing dye concentrations in sodium hydroxide pH 12 are submitted to a heating time of 330 min at 80 degreesC. Linear calibration curves can be obtained for RG19 dye concentrations from 5x10(-9) mol L-1 to 8x10(-8) mol L-1. The detection limit (3sigma) is 1x10(-9) mol L-1.