Table 4 : Summary of gel evidence showing successful PCR amplification of the V3-V4 region of the 16S rRNA gene using microbial DNA extractions from the preen oil samples of the indicated species. The PCR product from the song sparrow preen oil microbial DNA extract was the only PCR product that did not appear on any gel. Cells filled with black indicate amplified gene products from the species were not run on that gel.