Rayleigh Light Scattering study on interaction of protein with Beryllon IIand its application

A new quantitative determination of proteins using 2-(8-hydroxy-3, 6-dislph o-1 -naphthylazo)-1, 8-dihydroxynapphthalene-3,6-disulphonic acid (Beryllon II) by Rayleigh Light Scattering (RLS) has been developed. Under weak acid ic condition (pH 3.80) proteins can enhance the weak RLS of Beryllon greatl y and quantitatively at 380nm. This method is characterized with very high sensitivity, wide linear range of determination (0.10-32.40 mug ml(-1) for bovine serum albumin), rapidity, and simplicity tone step and common fluori meter). There is little or no interference from amino acids, most of the me tal ions or other coexistent substances. The method was applied to the dete rmination of protein in human plasma and the results are very close to thos e of the Coomassie Brilliant Blue method assay (CBB method).