Simple and sensitive determination of nucleic acid by Rayleigh light scattering technique with methyl green-CTMAB

Abstract

A method is presented for the determination of nucleic acid, based on the enhancement of Rayleigh light scattering (RLS) of methyl green (MG)-CTMAB in the <i>p</i>H range 6.9-7.2 at 414.0 nm. The enhanced intensity of RLS is proportional to the concentration of nucleic acid in the range 2.5×10^-8-2.0×10^-6g/ml for calf thymus (ct)DNA, 2.5×10^-8-2.0×10^-6g/ml for fish sperm (fs)DNA, 7.5×10^-8-2.0×10^-6g/ml for yeast (y)RNA. The detection limits (3σ) are 7.8, 2.6, 9.9 ng/ml for ctDNA, fsDNA and yRNA respectively. Besides its high sensitivity, it has some other advantages: simplicity of operation, commonality of spectrometer and reagents, good stability of chemical system and reproducibility. The procedure has been successfully applied to the determination of nucleic acid in synthetic samples.