Abstract: Based on the interaction of total protein with poly(diallyldimethylammonium chloride) (PDDA), a new method to determine the total protein in human serum was developed with the resonance light scattering (RLS) technique. Under appropriate conditions, the RLS intensity at the wavelength of 320 nm is directly proportional to the protein concentration in a range of 2.35×1 0^-8~1.17×10^-6 mol/L. The total protein in human serum was determined with the method mentioned above. The method was also compared with Bradford method and the results obtained were satisfactory.

Key words: resonance light scattering, poly(diallyldimethylam monium chloride), human serum albumin, human serum, total protein