METHODS:EGFP and TK were amplified by polymerase chain reaction and fused by splicing overlap extension. The fusion gene EGFP-TK was then subcloned to the sites Sal I and Cla I of pBABE-puro-lox to construct pBTKlox.

• 方法扩增EGFP及TK并采用重叠延伸拼接(SOE)法连接EGFP和TK,将EGFP-TK融合基因亚克隆至pBABE-puro-lox的Sal I和Cla I位点之间,构建成新载体pBGTKlox。