Genomic DNA from cecum (Ce), CoP (proximal colon), CoD (distal colon) and liver was examined for the presence of the Cre transgene and an internal control gene, as well as the wild-type APC allele, the floxed APC allele (APC LoxP), and the Cre-deleted APC allele (APC580D). Because genotyping was conducted on whole tissue containing epithelial and other cell types containing the Cre transgene, the floxed Apc allele is still visible even as the Cre-recombined Apc allele appears.