Roche produce Blunt or dA tail PCR product? - (Mar/07/2007 )
I am using the Roche expand long template PCR system to amplify the 6.4 kb PCR product. I want to know the PCR procdut produced by this system is blunt ended or with dA tail.
Is there anybody who worked with this system and very sure with the nature of the enzyme.
It's a mix of taq and a proofreader, produces a combination of blunt and -A.
taq on its own will produce about 70% A-tailed products. The 30% remainder is bunt end.
the proof reading polymerase component (pfu or pwo... can't quite remember which) will produce blunt end
So I would guess the amount of A-tailed producst is significantly less then 70%.
I don't know the relative amount of blunt vs tailed, but we have used this (and other mixes of proofreading/taq) for TOPO-TA cloning and always had sufficient colonies to work with.
Probably is pwo btw.