Hi, I have used Deep Vent in regular PCR (although NEB do not advocate it). I have always found that the 2mM MgSO4 is not right for the PCRs I have done. I always use Taq buffer and 1.5mM MgCl2. This works fine. Ive never found any use for the buffers and MgSO4 solutions supplied with Deep Vent. cheers Nick.