研究了微量脱氧核糖核酸与吖啶黄的加成反应,并对反应条件作了优化,基于在pH 6.5的B-R缓冲溶液中,脱氧核糖核酸(DNA)浓度与吖啶黄最大吸收波长444 nm处的吸光度线性降低的关系,建立了测定微量DNA的方法.在小于8.0 mg·L-1浓度范围内呈现良好的线性关系,相关系数为0.999 8,对3个模拟试样中DNA含量作了测定,结果的RSD值及回收率的测定结果分别在1.4%~3.0%及98.3%~104.0%之间.对此加成反应的机理也作了初步探讨.

The addition reaction of DNA with acridine orange was studied by spectrophotometry,and the conditions,i.e.the acidity,time of reaction and amount of acridine orange etc.for the reaction were optimized.As shown by the experimental results,the absorbance of acridine orange at 444 nm decreased with the increase of concentration of DNA added.In a B-R buffer solution of pH 6.5,linear relationship between the decrease in absorbance (ΔA=A0-A) and the concentration of DNA was found in the range within 8.0 mg·L-1 (r=0.999 8).Based on these facts,a spectrophotometric method for determination of micro-amounts of DNA was proposed.In the determination of NDA in 3 simulated samples,values of RSD′s (n=5) and recoveries were found in the ranges of 1.4%-3.0% and 98.3%-104.0% respectively.Furthermore,a brief discussion on the mechanism of the addition reaction was given.