Accurate measurement of human serum albumin by bromcresol purple dye-binding

The use of Bromcresol Green (BCG) to measure albumin is widespread despite the documented over-estimation by this technique in the clinically important low range. BCG binds to α & β globulins in a time-related manner causing significant over-estimation even at 18 sec after mixing. Bromcresol Purple (BCP) shares the desirable features of dye-binding techniques, yields a stable chromogen, and gives excellent agreement with immuno-chemical measurements of albumin. Alb ( BCP ) = 0.95 Alb ( RID ) + 2.5 The recently published method of Pinnock et al. (Clin. Chem., 1978,24,80) has been adapted to discrete analysers (Centrifichem 400, ABA-100). The optimized stable reagent and analytical conditions chosen ensure linearity to 60 g/L, and excellent precision (CV <2% at 30g/L). However, heparin plasma is unsuitable (turbidity develops) and animal albumin (bovine, equine, porcine) is grossly under-estimated. With these limitations, BCP-binding appears to be the method of choice for the rapid, precise, accurate and economical measurement of human albumin suitable for automated equipment. The use of Bromcresol Green (BCG) to measure albumin is widespread despite the documented over-estimation by this technique in the clinically important low range. BCG binds to α & β globulins in a time-related manner causing significant over-estimation even at 18 sec after mixing. Bromcresol Purple (BCP) shares the desirable features of dye-binding techniques, yields a stable chromogen, and gives excellent agreement with immuno-chemical measurements of albumin. Alb ( BCP ) = 0.95 Alb ( RID ) + 2.5 The recently published method of Pinnock et al. (Clin. Chem., 1978,24,80) has been adapted to discrete analysers (Centrifichem 400, ABA-100). The optimized stable reagent and analytical conditions chosen ensure linearity to 60 g/L, and excellent precision (CV <2% at 30g/L). However, heparin plasma is unsuitable (turbidity develops) and animal albumin (bovine, equine, porcine) is grossly under-estimated. With these limitations, BCP-binding appears to be the method of choice for the rapid, precise, accurate and economical measurement of human albumin suitable for automated equipment.