Restriction Enzyme Digest of PCR Product From Caco-2 Cells. The amplified PCR product for the apical calcium transporter from Caco-2 cells (see text) was digested with Bgl1 or BssHII restriction enzymes. Digestion with Bgl1 resulted in the generation of two smaller appropriately sized products (180 bp and 80 bp) as would be expected only if the PCR product was CaT1 due to the presence of this restriction enzyme cut site only in CaT1 but not ECaC1 in the region amplified (GenBank acc. no. AF365927 nucleotide location 545–803). BssHII digestion did not result in any smaller bands being observed. Thus was expected since this enzyme was not predicted to cut either CaT1 or ECaC1 (GenBank acc. no. AF304464) in the region of interest and thereby could serve as a negative control to exclude the possibility that nonspecific fragmentation of under the restriction digest conditions.