Why is an ice-incubation step included during reaction set-up when following the QuantiTect RT-PCR but not the QuantiTect PCR protocol.

The ice step is recommended to prevent non-specific reverse transcription during reaction set-up. Mispriming by Taq is not a concern in these cases because both QuantiTect RT-PCR and PCR kits contain HotStarTaq, a DNA polymerase that only becomes active following a 15 minute, 95 degree incubation step.