Objective:To construct the plasmid that can direct the synthesis of si-RNA like transcripts to specifically and effectively in hibit the mRNA level of human Hsp90βgene

and to compare the transfection efficiencies of the plasmids in different cell strains. Methods:Three 64 nt oligos corresponding to different regions in the target gene are chemically synthesized and annealed

then inserted into pSUPER EGFP1

proliferated by DH5a

and determined by endodigestion and sequencing. Three strains

HepG2、HUVEC and HeK293

were cultured. We then transfected the plasmids into the cells under different ratio of plasmid and Lipofectamine

and compared the transfection efficiencies of them by detection of EGFP Fluoresence. Results:The presence of positive recombinant clones was verified by double-digestion and sequencing. The bases inserted into the pasmids were correct.And the positive colonies were named as pSuper-Hsp90β1、pSuper-Hsp90β2 and pSuper-Hsp90β3. and the same condition

the constructed plasmid had the highest transfection efficiency in HeK293

and the lowest in HepG2 cells. Conclusions:The si-RNA synthesis plasmids targeting Hsp90β could be successfully constructed by using psuper plasmids

and the difference of their transfection efficiencies in different cells was significant.