Evaluation of a bromocresol purple method for the determination of albumin adapted to the DuPont aca discrete clinical analyzer

We evaluated a new method for the determination of albumin on the DuPont aca™ discrete clinical analyzer that utilized an albumin selective dye, bromocresol purple (BCP). This dye minimizes globulin interference that occurs with bromocresol green (BCG) methods that have long (>30 s) incubation times. Good correlation was observed between the new BCP method and two methods which do not show significant globulin interference: an immunological method and a rapid BCG method. Comparisons with alternate BCG methods (SMA 12/60, SMAC, and the aca) were generally not as good. The albumin results by the BCP method on specimens with elevated globulins were similar to results from the immunological and rapid BCG methods. The reference interval was 34–50 g/L. The between-day coefficient of variation ranged from 0.9 to 3.5% at three evaluation sites on 2 levels of 8 different control materials. The method was linear between 6–70 g/L. No interference was observed from hemoglobin at levels ⩽5.00 g/L or from bilirubin at levels