Effect of CPP-PNA (PNA2967) and Cat-Lip-PNA (PNA2968) on the skipping of exon4. JAR cells were incubated with PNA for 4 h in the serum free OPTI-MEM medium (without cationic lipids) in the absence or the presence of 120 μM chloroquine (CQ) and incubated further for 24 h after supplemented a growth medium to have 10% FBS concentration. Total RNA was extracted and subjected to RT-PCR using Exo3S and Exo5AS primers (see Table 2). Locations of the normally spliced form (Normal, 207 bp) and exon4-skipped form (Skipped, 131 bp) are indicated on the right of the pictures. Numbers under each lane indicate the amount of the skipped form relative to the sum of skipped and normal form.