Ethidium bromide-stained agarose gel showing PCR products from five different combinations of Ad species-specific primers. Lanes, from left to right:, respectively: M, molecular weight marker III (Boehringer Mannheim); species A-F, species A to F; A-D, F, species A, B, C, D, and F; B, D, E, species B, D, and E; B, C, E, species B, C, and E; B, C, D, species B, C, and D; Neg, template-free negative control. Numbers on the left are in base pairs.