Figure 1. Visualization of PCR results for a 130-bp region of COX1 with (A) no enrichment and (B) a PNA clamp to prevent amplification of python DNA.

In both (A) and (B), the first six reactions used extractions from python GI contents, the seventh used a python positive control, and the eighth used a mammal positive control. We observed successful amplification of the target locus for all samples when no enrichment was used (A), and all sequences were identified as python except for the mammal positive control. When we prevented amplification of python DNA at the target locus (B), only the mammal positive control was successfully amplified. This suggests that: (1) our DNA extractions were successful; (2) the PNA clamp effectively excludes amplification of python DNA; and (3) prey DNA is of insufficient quality in these samples to amplify at this locus.