Construction and identification of a cDNA expression library from Clonorchis sinensis

Objective To screen specific-antigen gene for diagnosis and antigen gene for candidate vaccine,a cDNA expression library of Clonochis sinensis(Cs) was constructed. Methods Total RNA from Cs was extracted and cDNA was synthesized by SMART TM cDNA library protocol.Products were digested by SfiⅠ,and fractionated with CHROMA SPINT 400 column. The cDNA with size of 0.4～4kb were recycled and ligated to λTriplEx2 Vector. The λphage packaging reaction for the ligations was performed to produce a unamplified library. After the unamplified library and the percentage of its recombinant clones was respectively tittered. The library amplification and the titer of the amplified library were executed, successively .Ten phages were randomly selected and amplified using primers from vector by PCR to test the quality of obtained library. Results The titers of unamplified and the amplified library are 7.5×10 7pfu/ml and 2.7×10 9 pfu/ml respectively.The percentage of recombinant was nearly 100% . Result of PCR indicated that all the selected phages possessed the recombinant cDNA , and that these cDNA are beyond 500bp. Conclusion A qualified cDNA library from Cs is constructed successfully .