Resonance light scattering technique for the determination of proteins with Congo red and Triton X‐100

Abstract

Resonance light scattering (RLS) of Congo red (CR) was greatly enhanced by BSA (HSA) in the presence of Triton X-100 (TX-100). In sodium citrate-HCl buffer (pH 2.7-3.0), the enhanced intensity of resonance light scattering at 360 nm was in proportion to the concentration of proteins [corrected] The linear relationship was obtained between the resonance light scattering intensity and proteins in the range 5.0 x 10(-8)-8.0 x 10(-6) g/mL and 1.0 x 10(-9)-6.0 x 10(-6) g/mL for BSA and HSA, respectively. Their detection limits were 1.4 x 10(-8) g/mL and 2.8 x 10(-10) g/mL (S:N = 3), respectively. Synthetic and actual samples were analysed satisfactorily.