Study of the interaction of protein and dibromomethyl-Arsenazo-Al(III) by Rayleigh light-scattering technique

Based on the weak Rayleigh light scattering (RLS) of the complex of dibromo methyl (DBM)-Arsenazo-Al(III) which can be enhanced by the addition of prot ein in weak acidic solutions, a novel method for the determination of prote in concentrations has been proposed by using a commonly used spectrofluorim eter. Four proteins, including bovine serum albumin (BSA), human serum albu min (HSA), lysozyme and egg albumin were tested. The dynamic range, for exa mple HSA is 2.5-50.0 mug ml(-1) and the 10 sigma determination limit is 83 ng ml(-1). This method has been applied to the determination of proteins in human serum samples, and the results are very close to those provided by c linical physicians. There is very little interference from amino acids, met al ions and other coexisting compounds. The assay is convenient, rapid, ine xpensive and simple. (C) 2001 Elsevier Science B.V. All rights reserved.