Fig. 2

PCR screening for validation of selected clones. PCR primers flanking PRF1 gene exon 2 designed to yield a 1.3-kb amplicon in nontargeted (wild-type) genome. Homozygous insertion of an expression cassette containing human ubiquitin C promoter driving the puromycin resistance gene yields a 2-kb amplicon (a). Analysis of PCR results on 1% agarose gel confirmed homozygous 2-kb insertion into PRF1 exon 2 in selected NK92 clones (b). Donor plasmid vector used as positive control and human control DNA as negative control