应用特异双引物法标记DNA探针

Labelling of DNA probes by specific double - primer method

作者应用位于探针DNA两端的两个DNA片段作引物,以探针DNA为模板,在大肠杆菌DNA聚合酶I的介导下,经过1—3次变性、退火和延伸过程,使探针DNA得到标记.3次实验结果表明,应用此法标记的DNA探针的比活性可以达到2×10^(14)cpm/g DNA,标记效率大于60％;而用缺刻翻译法标记的DNA探针,其标记效率只有22.7％.表明这是一种较好的DNA探针标记方法.

A new method called double-primer technic has been developed by the author. Two DNA fragments lo-cited at the two ends of the probe DNA were used as primers for the syntheses of radioactive probes. It was found in three experiments that the radioactivity of the DNA probe labelled according to this method was 2 × 1014 cpm/g DNA, with a radioincorporation rate over 60% while that of nick translation was only 22.% These results suggest that the double-primer tcchnic is an ideal approach to the labelling of DNA probes with high radioactivities.