Quenching Effect of Nucleic Acids on Resonance Light Scattering of Colloidal Sliver Chloride and Its Application
- 化学化工－已发表论文 
报道了一种测定水溶液中核酸的方法，该法基于核酸对氯化银溶胶共振散射光的猝灭作用。在理想测定条件下，散射光的猝灭程度正比于核酸的浓度，三种核酸（ｃａｌｆ ｔｈｙｍｕｓ ＤＮＡ， ｈｅｒｒｉｎｇ ＤＮＡ ａｎｄ Ｙｅａｓｔ ＲＮＡ）的线性范围分别为 ０－ ２０μｇ／Ｌ，０～ ６０μｇ／Ｌ和 ０～ ８０μｇ／Ｌ，检 测限分别为 ０．６５ μｇ／Ｌ，１．１μｇ／Ｌ和 １．９ μｇ／Ｌ。 ６种合成样品的测定结果令人满意。机理研究结果表明，核酸中的碱基（尤其是嘌呤碱）同银离子具有很强的结合能力，这种结合影响了氯化银的沉淀平衡，导致了氯化银溶胶共振散射光的猝灭。A novel quantitative method. based on the quenching of resonance light scattering (RLS) of colloidal silver chloride by nucleic acids, has been developed for the determination of nucleic acids in aqueous solutions. Under optimal conditions, the pouched intensity of RLS is proportional to the concentrations of calf thymus DNA, herring DNA and yeast RNA in the ranges of 0 ~ 20 x 10-9 g/mL, 0 ~ 60 x 10-9 g/mL and 0 ~ 80 x 10-9 ug/L, respectively. The limits of detection for the three nucleic acids are 0.65 x 10-9ug/L, 1.1 x 10-9 g/mL and 1 .9 x 10-9 g/mL, respectively. Six synthetic samples were analyzed with satisfactory results. mechanism studies showed the quenching effect of nucleic acids on in of collidal silver chloride was possibly due to the equilibrium shift of Ag+ + CI- = AgCl (existed in colloid formation) when nucleic acids whose bases, especially purines, having power to bind silver ions were added.