TA cloning nightmare

Dr. Duncan Clark duncan at genesys.demon.co.uk
Fri Mar 8 05:37:47 EST 1996

In article <DnwMrE.Dp4 at pfizer.com>, "Catherine I. DiOrio"
< at pfizer.com> writes
>The polymerase you used to amplify your PCR product, KlenTaq, has 
>3'to 5' exonuclease activity, which is desireable for improved 
>sequence accuracy.  However, I have found that this exonuclease 
>activity likely removes the A- overhangs which are created by 
>ordinary Taq polymerases.  I have had luck with TA cloning vectors 
>only using ordinary Taq polymerase.

KlenTaq does not have 3'-5' exonuclease activity. It is a deletion of
Taq removing the 5'-3'exo. There are a number of KlenTaq varients around
removing say between 210 and 250aa's from the N-terminal end of Taq. You
may be confusing this with KlenTaq-LA which is a mix of Klentaq and a
proof-reading pol. 

DNAmp Ltd.
Licensed PCR enzyme manufacturer
The problem with being on the cutting edge is that you occasionally get 
sliced from time to time....

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