Figure 1.

Melting curves of RecA and Nidogen molecular beacon probes in the presence of specific or unrelated targets. Melting curves between the RecA1, RecA2 and RecA3 molecular beacons (A-C) in the presence of complementary target sequences (green lines), in the presence of unrelated Nidogen target sequence (blue lines) or in the absence of any target (buffer only control, red lines) were generated. The fluorescence analyses indicate that the molecular beacons exist either as hybrids with their targets, exhibiting high fluorescence or are in the free state in the form of a stem-loop structure with fluorescence quenched at a temperature range of 55–75°C. A similar analysis of a Nidogen molecular beacon depicted a temperature and fluorescence profile (D), which is similar to the RecA3 molecular beacon.