应用PCR—SSCP技术从显微切割的人染色体17q11—12探针池批量分离单拷贝片段的研究

将ＤＮＡ单链构象多态（ＳＳＣＰ）检测的原理，应用于“显微切割的人染色体１７ｑ１１—１２探针池”批量分离单拷贝片段，取得了很好效果。从筛选出的７４个次级单拷贝中有效地鉴定出３７个非同源的单拷贝片段。这比传统的仅限于长度比较而确认的非同源单拷贝片段（１２个）多出２５个．其中部分已经ＤＮＡ测序证实。结果提示：采用ＳＳＣＰ技术区分相似分子量单拷贝片段的同源性，可显著地提高从“显微切割探针池”分离和克隆非同源单拷贝片段的效率。本文还将一部分单拷贝片段作为探讨，与人基因组ＤＮＡ的限制性片段作Ｓｏｕｔｈｅｒｎ印迹杂交，结果均只显示单一杂交带，说明单拷贝ＤＮＡ片段的结论是可靠的。

Batch isolation of single-copy DNA fragments by using PCR-SSCP from the probe pool of human chromosome 17q11-12generated by microdissection

In the present study, the principle of detecting single strand comformation polymorphism(SSCP) has been successfully used for batch isolation of single-copy DNA fragments from the probe pool of chromosome 17q11-12 generated by microdissection. A total of 37 non-homologous single-copy fragments were identified from 74 possible single-copies. This was 25 more than that identified (12 fragments) by the conventional length comparation method. 4 out of these 37 single copies were sequenced. The result indicated that the SSCP technique is capable of differentiating the single-copy fragments with similar molecular weight, and increasing remarkably the isolation efficiency of non-homologous single-copy fragments from the probe pool generated by microdissection. In addition,six single-copy fragments have been used as probes to hybridize with the Southern blot of human genomic DNA,and only single or at most two hybridization bands were seen for each sample. The result suggested that the singlecopy DNA fragments identified by the PCR-SSCP are valid indeed.