Partial strands synthesizing leads to inevitable aborting and complicated products in consecutive polymerase chain reactions (PCRs)  

作　　者：LUO Rui1,2 & ZHANG DaMing 1 State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China 2 Graduate University of Chinese Academy of Sciences,Beijing 100049, China 

出　　处：《Science China(Life Sciences)》2007年第4期548-556,共9页中国科学（生命科学英文版）

基　　金：Supported by the National Natural Science Foundation of China (Grant No. 30430030)

摘　　要：Various abnormal phenomena have been observed during PCR so far. The present study performed a series of consecutive PCRs (including many rounds of re-amplification continuously) and found that the abortion of re-amplification was inevitable as long as a variety of complicated product appeared. The aborting stages varied, according to the lengths of targets. Longer targets reached the abortion earlier than the shorter ones, marked by appearance of the complex that was immobile in electropho-resis. Denatured gel-electrophoresis revealed that the complex was mainly made up of shorter or partially synthesized strands, together with small amounts of full-length ones. Able to be digested by S1 nuclease but unable by restriction endonucleases (REs), the complex was proved to consist of both single regions and double-helix regions that kept the complex stable thermodynamically. Simulations gave evidence that partial strands, even at lower concentration, could disturb re-amplification effec- tively and lead to the abortion of re-amplifications finally. It was pointed out that the partial strands formed chiefly via polymerase’s infidelity, and hence the solution to lighten the abnormality was also proposed.Various abnormal phenomena have been observed during PCR so far. The present study performed a series of consecutive PCRs (including many rounds of re-amplification continuously) and found that the abortion of re-amplification was inevitable as long as a variety of complicated product appeared. The aborting stages varied, according to the lengths of targets. Longer targets reached the abortion earlier than the shorter ones, marked by appearance of the complex that was immobile in electropho- resis. Denatured gel-electrophoresis revealed that the complex was mainly made up of shorter or partially synthesized strands, together with small amounts of full-length ones. Able to be digested by S1 nuclease but unable by restriction endonucleases (REs), the complex was proved to consist of both single regions and double-helix regions that kept the complex stable thermodynamically.Simulations gave evidence that partial strands, even at lower concentration, could disturb re-amplification effec-tively and lead to the abortion of re-amplifications finally. It was pointed out that the partial strands formed chiefly via polymerase’s infidelity, and hence the solution to lighten the abnormality was also proposed.

关 键 词：consecutive PCR abnormal complicated product PARTIAL STRAND synthesis DISTURBING effect PCR-mediated recombination long distance PCR 

分 类 号：Q78[生物学—分子生物学]