RT-PCR method specific for the detection of transgenic CFTR mRNA in the presence of transgene plasmid DNA and endogenous CFTR mRNA.

A major problem with experiments involving the correction of cystic fibrosis by gene transfer has been reliably detecting the transgenic message and distinguishing this from an endogenous message and from vector DNA. We have exploited the SV40 small T antigen intron present in an expression vector containing the CFTR cDNA (pCFAS) using a primer directed to the spliced sequence to allow specific and precise detection of the transgeneic message.