Figure 2.

Fluorescence readings during real-time PCR with either a linear or a hairpin fluorogenic primer. Fluorescence was measured at 25°C before the PCR, during a preheating step at 94°C, at 55°C during each cycle of PCR, and finally at 25°C after the cycling. (A) PCR using a FAM-labeled linear reverse primer (primer set 1, Table 1). (B) PCR using a FAM-labeled hairpin reverse primer (primer set 2, Table 1). PCRs were performed on an ABI 7700 with 10⁶ copies of cloned IL-4 cDNA using similar conditions and with the same unlabeled forward primer. (C) Plot of temperature versus detector readings.