Pfu polymerase in PCR

Dr. Duncan Clark duncan at genesys.demon.co.uk
Tue Feb 11 04:38:16 EST 1997


In article <fof1-1002971723410001 at saentis.biologie.uni-konstanz.de>,
"Frank O. Fackelmayer" <fof1 at chclu.chemie.uni-konstanz.de> writes
>Pfu is a proofreading POLYMERASE. It will NOT degrade your DNA in presence
>of nucleotide triphosphates (this is why you should add the polymerase
>last). Only after misincorporation of a nucleotide, Pfu will remove this
>nucleotide and then continue polymerizing. 


Not quite true. Unannealed primers are single stranded and even in the
presence of dNTP's the 3-5 exonuclease will attack them. When they are
annealed as a duplex in the prsence of dNTPs polymerisation occurs and
the exonuclease is inhibited from action but only on the duplex.

Duncan  
--------------------------------------------------------------------------------
The problem with being on the cutting edge is that you occasionally get 
sliced from time to time....

Dr. Duncan Clark
DNAmp Ltd.
TEl/FAX 01252376288
http://www.dnamp.com
http://www.genesys.demon.co.uk



More information about the Methods mailing list