Effects of surfactants and enzymes on the direct determination of protein on fabric using the BCA reaction

Abstract A simple and direct determination method for protein on fabric by measuring the surface reflectance of the bicinchoninic acid (BCA) reaction color has been reported. This study investigated the effects of four synthetic surfactants, six sodium fatty acids and one enzyme, as the coexisting substance on the direct determination of protein in cotton fabrics. The influence of the coexisting substance to the BCA reagent was examined. Then, seven coexisting substances present in detergents were selected, and the reflectance of reacted test swatch by protein and each coexisting substances were also measured, and then compared to the values obtained for protein alone. With the exception of sodium dodecyl sulfate and lauric acid, the concentration of the surfactants used in this study had little effect on protein determination. At low protease concentration there were no significant effects on the BCA method and determination.