<正>在分子生物学研究中,基因克隆和分子杂交的探针制备等操作常需分离与已知DNA序列邻近的未知序列,热不对称交错PCR(简称TAIL PCR)反应技术能够较好地解决上述难题。该技术通过3个嵌套的特异性引物分别和简并引物组合进行连续的PCR循环,利用不同的退火温度选择性地扩增目标片段,所获得的片段可以直接用做探针标记和测序模板。TAIL PCR技术简单易行,反应高效灵敏,产物的特异性高,重复性好,能够在较短的时间内获得目标片段,已经成为分子生物学研究中的一种实用技术。笔者综述了TAIL PCR反应的原理、引物设计、反应条件设置及产物分析。

Isolation of DNA fragment adjacent to a known sequence is a tedious task in genomerelated research.Thermal asymmetric interlaced PCR(TAILPCR) is an efficient technique for isolation of target DNA segments flanking known sequences.It was utilized three nested sequencespecific primers with a shorter arbitrary degenerated(AD) primer respectively.Specific products can be amplified through continuous cycles of amplification at different annealing temperature.The amplified products are suitable for either hybridization probes or sequencing templates.TAILPCR technique is very simple and highly efficient.The specific products can be obtained again in the same PCR mixture and the same PCR condition.All the TAILPCR reaction need only a few time as in one day.It has become a powerful tool in a genomic analysis.This article presents the principle and protocol of TAILPCR.Methods for primers design and products selection are also discussed.