Platinum Taq, 3' A and proofreading - (Feb/02/2006 )

"Taq DNA Polymerase will incorporate a deoxynucleotide (often an adenosine) in a template independent manner on the 3' end of the new DNA strand."

Does anyone know or suspect whether this would also be true for Platinum Taq (Invitrogen)? They don't say but I suspect it is since Platinum Taq is just Taq complexed with an antibody that inhibits polymerase activity.

Also, I am wanting to use a pcr product for blunt-end cloning, hence I want to things: proofreading capability and blunt ends. Would I be better off using Vent over Platinum Taq?

Platinum Taq is a mixture of Pfu and Taq, and will have activity in adding 3' A's. If you need blunt product, pure Pfu or similar enzymes are needed, such as Pfu Turbo, Pfu Ultra, Vent, or Phusion.

I don't think it does contain Pfu:

http://www.invitrogen.com/content.cfm?pageid=554

Platinum taq is just regular taq with an antibody to inhibito polymerase activity before initial denaturation. During denaturation, this antibody is destroyed and has no influence on taq activity anymore. So this one leaves the extra A.

Phage was probably talking about "platinum taq high fidelity" which indeed is a mixture of taq and a proofreader (not Pfu, pfu is sold by fermentas, stratagene and promega, but not by invitrogen, they have pfx). Platinum taq high fidelity should create a mixture of PCR products with extra A (thanks to taq) and some blunt ended (thanx to the proofreading enzyme).

For blunt end cloning, use pfu, pfx, pfu turbo, pfu ultra, phusion, vent, pwo, tgo...

Thanks vairus.

Sorry, yes, I was talking about Platinum High Fidelity. My mistake.

I have used Pfx, i recommend you using this enzyme for blunt-end PCR product.
B.