Potential interference of hydrogen peroxide in the 2,2'-bicinchoninic acid protein assay.

At a concentration of 20-800 nmol/0.1 ml hydrogen peroxide instantly reacts with a 2,2'-bicinchoninic acid copper color reagent. It also reacts with a reformulated reagent at pH 7 but the color develops less rapidly. While the effect may interfere with protein estimations at alkaline pH, the effect of pH 7 may be used to determine the possible extent of hydrogen peroxide interference after treatment with catalase.