Micro-determination of nucleic acids with a simple probe manganese chloride based on the fine enhanced resonance light scattering

Manganese chloride can form large particles with nucleic acids by electrostatic forces, which results in strong enhancement of resonance light scattering (RLS) signals. Based on this phenomenon, a novel and very simple assay of DNA was established. The work conditions have been investigated including the concentration of probe, the acidity of solution, the effect of ionic strength and the selectivity. In acidic solution, the enhanced RLS intensity at 389.5 nm was proportional to the concentration of nucleic acids in the range 0.05-10.0 mu g ml(-1) for both ctDNA and fsDNA and 1.0-10.0 mu g ml(-1) for yRNA. The limits of detection (LOD, 3 sigma) were 0.17, 0.13 and 0.53 ng ml(-1) for ctDNA, fsDNA and yRNA, respectively. Synthetic samples were determined satisfactorily. (C) 2006 Elsevier B.V. All rights reserved.