Analyte and matrix problems in the calibration and quality assessment of the bromocresol green method for albumin in serum

Different batches of bromocresol green were used in a study of several modifications of the bromocresol green method for serum albumin. No major batch variation was observed. Lyophilized animal sera and a certain batch of lyophilized human sera, however, responded differently from a pool of fresh human sera when the method was modified. These phenomena should be taken into account in calibration procedures and in quality assessment.