[Amplification, clone and identification of the specific fragments of tumor metastasis-suppressor gene nm23-H1 and nm23-H2].

A series of DNA primers specific for the specific fragments of nm23-H1 and nm23-H2 were designed and synthesized. The specific fragments of nm23-H1(185 bp) and nm23-H2(145 bp) were amplified from human blood DNA by using polymerase chain reaction (PCR). The recovered PCR products were treated with Klenow fragment, inserted into pGEM-3zf(+) vector with blunt-end ligation, and then transformed into competent cell JM109. The positive colonies were directly identified by colour screening on indicator plates. The recombinant plasmids were digested by Alu I and identified by PCR. The results showed that the authors had obtained the specific fragments of nm23-H1 and nm23-H2 respectively, and these specific fragments could be used for study the expression of nm23-H1 and nm23-H2 seperately.