Microdetermination of proteins by enhanced Rayleigh light scattering spectroscopy with morin

Under acidic conditions, the reaction between 3,5,7,2′,4′-pentahydroxyflavone (morin) and proteins enhances the weak light scattering of morin drastically. The enhanced light scattering intensity is proportional to the content of proteins. This fact is the basis of a new method for the quantitative analysis of proteins. The linear range is 0.45–7.15 and 0.46–11.14 μg/mL for BSA and HSA, respectively. The relative standard deviation is 3.76% (n = 12) for BSA in the middle of the linear range. The results of this assay for human serum samples were comparable with those from the traditional method (CBB method). There is almost no interfere from amino acids and most of the metal ions. The scattering spectrum of morin was also discussed. Received: 11 October 1998 / Revised: 18 February 1999 / Accepted: 24 February 1999