近红外分光光度法测定核酸

Determination of Nucleic Acids by a Near-IR Spectrophotometric Method

以阳离子型近红外花菁染料做为生色探针 ,研究了该染料与核酸的结合反应 .在 p H6 .0的条件下 ,该染料在 771nm处有最大吸收峰 ,在核酸存在下 ,其吸收峰显著下降 ,而在 6 4 0 nm处出现新的吸收峰 .据此 ,以该近红外花菁染料为生色探针 ,在 771nm处依其吸光度的下降可定量测定核酸 .SM DNA的线性响应范围为 6 0～ 2 0 0 0 ng/ m L ,yeast RNA的线性响应范围为 10 0～ 2 0 0 0 ng/m L;检测限分别为 30 ng/ m L及 50 ng/ m L;六次平行测定 DNA(4 50 ng/ m L)的相对标准偏差为3.4 % ,测定 RNA (4 50 ng/ m L )的相对标准偏差为 3.7% ,方法具有较高的灵敏度 .用于合成试样分析 ,结果满意 .

A cationic near IR cyanine was used as a chromic probe and its binding reaction with nucleic acids was studied. In the medium of pH 6.0, the near IR cyanine showd a decrease in absorption at its maximal absorption peak (771nm) on binding to nucleic acids, and a new absorption peak appeared at 640 nm. Based on the fact, a novel near IR spectrophotometric method for the determination of nucleic acids was developed. The calibration graphs are linear over the range 60~2 000 ng/mL for Salmon Sperm DNA, 100~2 000 ng/mL for Yeast RNA, respectively. The detection limits is 30 ng/mLfor Salmon Sperm DNA, 50 ng/mL for Yeast RNA, respectively.