Problems with Promega Taq

neale at neale at
Fri Jun 4 11:36:52 EST 1993

In article <121481 at>, pfoster at (Patricia Foster) writes:
> Hi Netters,
>  A few weeks ago, robert at (Robert Coelen)
> posted:
>>A friend of mine in the next building suspects the storage buffer
>>of a batch of Taq from Promega is faulty: The lot number is 28330A
>>and the expiry is 02/95. Has anyone else experienced any problems
>>with this ?
>  So far, no response on the Net.  So I would like to reinstate a
> similar query.  I am having trouble with Promega's Taq lot number
> 287503, expiry date 1/95.  I bought it at a discount through Fisher.
> Anybody else having problems?  This is not a trivial matter as I
> bought a large amount, costing $800, and can't complain to Promega
> for the obvious reason.
>   A related question is:  is it only my impression or have other
> people felt that stuff you buy from normally reputable companies
> turns to junk when they sell it through the big supply houses?  Are
> they unloading substandard stuff on us?

Well, I can add my impressions to this discussion. First, If you are unhappy
with the product (for whatever reason) and you have documentation to show your
disatisfaction there is no reason not to complain to your Fisher
representative. Our representative is VERY good at getting replacement
enzyme/credit etc. Never hesitate to show your dispeasure with a product, you
will only lose in the long run.

Second, Promega ships different 10 x buffers depending on the kind of Taq pol
preparation. One Taq preparation lacks Triton, and you must be careful to use
th e appropriate buffer. This is what I mean about having appropriate
documentation/evidence on hand that you have not slipped up somewhere.

Third, we do see differences between Promega Taq and Cetus Taq. We see more
non-specific bands with Promega enzyme. Recently we have gone back to using
Cetus taq for all demanding work where we need to know what's going on (and
isn't that most to all of the time!). It's more expensive but less time is
wasted wondering obout results.

Hope this is of use to all users.

Geoff Neale                (no affiliation with either company)

St.Jude Children's Research Hospital
Memphis TN

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