Bromcresol purple method for serum albumin gives falsely low values in patients with renal insufficiency.

In patients with renal insufficiency, the BCP method underestimated the serum albumin. In non-renal patients, the BCP method gave albumin results in good agreement with the immunological method. The underestimation did not appear to be related to the degree of renal impairment. The interferent appears to act by preventing the binding of BCP to albumin. The BCG method is much less susceptible to this interference.