Comparison of mNUS activity in Tera-1 and HEK293 cell lines in Sleeping Beauty transposition. (A) Overall scheme of the transposition assay. Only those cells that receive a genomic insertion of a puromycin resistance cassette may grow and form colonies when exposed to antibiotic. In case of random, non-SB100X-mediated genomic integrations, the number of colonies is relatively low, whereas when SB100X transposase gene is active the number of colonies is significantly higher. (B) Representative colony number screens. Average colony numbers for each type of experiment are shown below the representative plates.