Induced skipping of mouse dystrophin exon 23 with overlapping PMOs directed at the donor splice site. Immortalised H2K-mdx myotubes were transfected with PMOs at the concentrations indicated and incubated for 24 hours before total RNA was extracted. Nested RT-PCR was undertaken to amplify exons 20 and 26. The full-length and exon 23 deleted transcripts are represented by products of 901 and 688 bp respectively. The band of 542 bp corresponds to dystrophin gene transcripts missing both exons 22 and 23 and has been previously reported [9, 36].