Does RNA - PCR ??

[Steven Sullivan]

Duncan Clark (Duncan at genesys.demon.co.uk) wrote:
: In article: <DBxnyo.Gn3 at midway.uchicago.edu>  rmoldwin at midway.uchicago.edu writes:

: > I also have seen several reports of RT activity in Taq.  Perhaps, it varies 
: > according to the manufacturer, and the specific origin of the Taq, e.g. 
: > recombinant/modified vs. wild type.  In my lab, we very rarely see this RT 
: > activity when using standard Perkin Elmer recombinant AmpliTaq, which PE 
: > reports in their catalog to have "minimal, low" RT activity.  AmpliTaq is 
: > modified from the wild-type Taq, but I can't determine what the difference is 
: > from their literature.

: AmpliTaq is not modified at the aa level just a recombinant version with 
: modified codon usage. It has the same level of RT activity ie low.

: As far as I am aware all thermus polymerases show a level of RT activity, but
: some are better than others ie Tth from Thermus thermophilus HB8. Most have
: an extremely poor level of RT activity. 

: On a similar note all thermus pols have the terminal transferase activity ie
: they add a single base to the 5' end of the PCR product which is usually (but
: not always) a T.

: Duncan   

A T?  I thought it was usually an A.