The products of PCR werenamed Sa and Sb, of 2.1Kb and 2.3Kb respectively. Sa was inserted in EcoR I andKpn I sites after Sb was cloned in KpnI and PstI multiple cloning sites of the samepUC18 plasmid.

• 1Kb和2.；3Kb两个片段，经酶切鉴定后，先后插入到pUC18质粒载体上的EcoRI和PstI多克隆位点上，构建了重组质粒pUC-S。