Abstract
Pi series of recombinant plasmids and retroviral vectors containing human clotting factor IX (hFIX), cDNA were constructed, and the efficiency of different promoters and enhancers in various constructors were compared. LTR promoter of MoMuL V showed a high transcription ability in mouse and rat fibroblasts, though CMV promoter has a better transcription ability in rabbit and human skin fibroblasts. The intron from both IL-2 gene and hFIX gene supposed to increase the expression level of hFIX in vitro was also studied. The coadjutant effect of double promoters and the combination use of selective gene in the constructors were also investigated.