中文摘要：

基于PCR的染色体步移（PCR-Walking）方法已有许多种,包括反向PCR、连接介导的PCR、随机引物PCR等.在众多的方法中,经常存在由通用引物引起的单引物非特异扩增现象.本文综述了连接介导的PCR-Walking中单引物扩增的形成原理及克服方法.克服单引物扩增主要是使接头引物在DNA两端的接头上只有1个结合位点,从而避开单引物扩增.常用的方法有3′端加氨基修饰的不对称接头、泡泡状接头或Y字型接头及单寡核苷酸接头等方法.还介绍了2种利用通用引物非特异扩增克隆目的序列的方法：引物错配法及基于RAPD原理的单引物PCR法.

英文摘要：

Chromosome walking adopted a variety of PCR methods,including inverse PCR,ligation mediated PCR,arbitrarily primed PCR.Non-specific amplification by the universal single primer was common in these methods.The problems of single primer amplification and the preventive strategies were reviewed in this paper,primarily to design primers with only one binding site on the two end adaptors of the DNAs.Bubble-or Y-shaped,as well as single oligonucleotide adaptors with 3′ modifications of an amino group were commonly used.Mismatched primer and single primer PCR methods based on RAPD were also discussed.