RT-PCR analysis of SULT1C3 mRNA content in human tissues and LS180 colon adenocarcinoma cells. PCR primers were designed to sequences in exons 6 and 7b (A). If the SULT1C3 transcript contained exon 7b, but not 7a, 8a, or other intervening sequence, the PCR reaction should have generated an amplicon of 231 nt. (B) A fragment of >500 nt was generated from the colon, small intestine, and LS180 RNA samples. Amplicons of ∼800 nt are visible in the skeletal muscle and placenta RNA samples.