For highest fidelity, we recommend Phusion® DNA polymerase (NEB #M0530) Q5® High Fidelity DNA Polymerase (NEB #M0491). For long RT-PCR product or difficult RT-PCR amplicon, we recommend LongAmp® DNA polymerase (NEB # M0323). For RT-PCR product smaller than 4kb, we recommend OneTaq® DNA polymerase (NEB # M0480).
