A hot start alternative for high-fidelity DNA polymerase amplification mediated by quantum dots.

Quantum dots (QDs) are of great interest due to their unique chemical and physical properties. Recently, a hot start (HS) polymerase chain reaction (PCR) amplification performance based on QDs with a high-fidelity Pfu DNA polymerase has been reported. However, whether QDs can trigger HS effects with other high-fidelity or conventional DNA polymerases is yet to be understood. In the present study, we studied the QD-triggered HS effects with four high-fidelity and three conventional DNA polymerases, and the HS effect comparisons among them were also made. It was found that QDs could trigger a distinct HS PCR amplification performance with all the four tested high-fidelity DNA polymerases, and specific target DNA could be well amplified even if the PCR mixture was pre-incubated for 2 h at 50°C. On the contrary, the HS effects were not prominent with all the three conventional Taq DNA polymerases. Specifically, the fidelity of Pfu is not sacrificed in the presence of QDs, even after a 1 h pre-incubation at 50°C before PCR. Furthermore, the electrophoresis results preliminarily demonstrated that QDs prefer to adsorb high-fidelity polymerases rather than conventional ones, which might result in the QD-triggered HS effects on PCR performance by using high-fidelity DNA polymerases.