FIG. 1.

PCR products for G3PDH (400 bp) and IFN-γ (342 bp). Reaction mixes (25 μl) containing 2 μl cDNA sample or 10.5 μl of G3PDH (A) or IFN-γ (B) standard cDNA solution were amplified simultaneously for 35 cycles as described in the text. Then, 15 μl of each reaction product was separated by electrophoresis in a 1% agarose gel containing ∼1 μg of ethidium bromide per ml. Lanes 1, 14, 15, and 28 (a and b), 250-bp ladder molecular weight marker (MW); lanes 2 to 13: G3PDH (A) and IFN-γ (B) PCR products from four aliquots (1 to 4) of a feline tonsil homogenate, each performed in triplicate; lanes 16 to 24, G3PDH (A) and IFN-γ (B) PCR products from sequential 1-in-4 dilutions of the G3PDH or IFN-γ standard solution (10⁶ U/10.5 μl); lane 26 (A and B), negative control (Neg) containing purified water in place of cDNA template solution; lanes 16 and 27 (A and B), empty.