Fig. 2

PCR screening steps for detection of pF508 correction. a Ethidium bromide stain of the gel showing positive amplification of the left homology arm of the targeted P allele. b In a similar fashion, gel image showing positive clones for amplification of the right arm. In both a and b, positive PCR reactions correspond to PCRs performed with same test primers on the control vector as a template, which contains adjacent genomic sequences to the 5’ end of the 5’ arm and the 3’ end of the 3’ arm. c BglII cut of the 5’ arm, confirming the presence of P recombined allele on positive clones. d PCR result of the targeted region after elimination of the selection cassette by transposase expression. Band size confirms elimination of the transposon-based double selectable marker from the homologous integration site