pYEMF,a pUC18-Derived <Emphasis Type="Italic">Xcm</Emphasis>I T-Vector for Efficient Cloning of PCR Products

A 1330-bp DNA sequence with two XcmI cassettes was inserted into pUC18 to construct an efficient XcmI T-vector parent plasmid, pYEMF. The large size of the inserted DNA fragment improved T-vector cleavage efficiency, and guaranteed good separation of the molecular components after restriction digestion. The pYEMF-T-vector generated from parent plasmid pYEMF permits blue/white colony screening; cloning efficiency analysis showed that most white colonies (>75%) were putative transformants which carried the cloning product. The sequence analysis and design approach presented here will facilitate applications in the fields of molecular biology and genetic engineering.