Problems with Promega Taq

Dr. S.A.J.R. Aparicio saparici at
Wed Jun 2 05:17:17 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?
> Patricia L. Foster
> Boston University School of Medicine
> Boston, MA USA
> pfoster at

We have had problems with Promega Taq, to the extent that we stopped using it.

In standard amplifications where primers are specific and template is 
plentiful and clean, it seemed to work fine, but when we tried using it for
complex targets with degenerate primers, the expected products were either
poorly amplified or not at all, compared with other Taq polymerases. The 
real issue seemed to be one of batch to batch variation - some batches seemed
ok, others didn't. I only use Cetus taq now, I think we can justify the 
expense because the product is of consistently high quality,

My colleagues down the corridor from us had the same experiences and have moved
to other suppliers.

I don't work for or have affliations to any company whatsoever.

Sam Aparicio
Molecular Genetics Unit
saparici at

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