FIG. 7.

RT-PCR analysis of the products of in vitro splicing. RNA was isolated from the position of spliced exons in a preparative version of the experiment shown in Fig. 6, reverse transcribed using a primer near the 3′ end of the precursor, and PCR amplified using a nested 3′ primer and a 5′ primer in the first exon, followed by denaturing gel electrophoresis to determine the sites of splicing. Due to differences in RNA recovery and amplification, differences in band intensities between lanes are not quantitatively meaningful.