RT-PCR analysis of potential mesothelin exon 13 splicing differences between transcript variants 1 and 2. A. Diagram of the PCR strategy, showing predicted size of amplified products from transcript variants 1 and 2. PCR primers (Table 1, line 2) are indicated by arrows. B. Agarose gel analysis of representative RT-PCR results. Lane M, molecular size marker; Lane 1, HeLa; Lane 2, OVCAR-3; Lane 3, Caov-4; Lane 4, SKOV-3; Lane 5, UCI 101; Lane 6, AsPC-1; Lane7, PANC-1; Lanes 8–9, two individual normal human ovaries; Lanes 10–14, five individual primary ovarian tumors; Lane 15, no template PCR control.