Li, K.-J., Garoff, H.
Notes: To assess the ability of a cytoplasmic Semliki Forest virus (SFv) expression system to generate an RNA for packaging containing an intron, the promoter, intron, CAT gene and poly A signal of the pCAT® Control Vector was inserted into a SFv vector. The SFv sequences and the CAT sequences were transcribed in vitro and co-transfected into BHK-21 cells with SFv vectors containing the Moloney murine leukemia virus packaging proteins. This method produced retrovirus particles that were of high titer and were used to infect NIH 3T3 cells. The CAT gene expression in the NIH 3T3 cells was measured with the CAT Enzyme Assay System. The presence of the intron in the infected cells was confirmed by isolating total RNA and performing RT-PCR with primers that could distinguish whether or not the cells got the CAT gene with the intron. RT-PCR was performed with the Access RT-PCR System. (0795)