pGEM-T woes

[Rae Nishi]

Here's a follow-up on the pGEM-T story.  I received a number of email
messages in addition to this post.  Three messages warned me of a lots
of pGEM-T contaminated by another plasmid; one reiterated this story of
a deletion in the entire multiple cloning site.  The deletion that we
found wasted one graduate student's time for about 2 mos.  The last
thing we did with the most recent batch of pGEM-T was to do a side- by
-side comparison with PCR II (the Invitrogen vector) since the rep I
talked with at Promega had intimated we could not ligate and transform
properly.  We took the same PCR product and ligated it to pGEM-T or PCR
II and transformed both into our own home-made competents.  We picked
10 colonies at random from each plate and did mini-preps.  5 of the 10
in PCR II had our PCR product as an insert; NONE of the 10 in pGEM-T
did.  Good by Promega.  I've wasted enough time.

Rae Nishi
Dept. Cell Biology & Anatomy
Oregon Health Sciences University
Portland Oregon 97201
**that's Orygun, NOT Ora-Gone**