cloning into Casper

Richard Friedman friedmrd at
Fri Nov 17 08:53:01 EST 1995

In article <47uf3e$oqk at>, S. Bartoszewski wrote:

> >myersm at
> I used a vector similar to Casper, and I had very low efficiency in cloning 
> fragments larger than ~10 kb.  In some cases constructs rearranged.  I found
> out that, the P-element flanks used in the vector were taken from its 
> insertion into white gene.  Since the vector contains also white gene, these
> sequences (~200 and ~400bp) are repeated and may enable intramollecular
> recombination, which I could observe.  I used E.coli DH5-alfa.  You may 
> check Casper's sequence, whether it contains direct repeats.  Slawek.

Out of curiosity, which vector are you using. I am trying to clone large
fragments into pBecky Blocker 5 ( a Casper derivative) and have used JM109
to transform.

Friedmrd at or rfriedma at
* "This Genie gig has it's ups and        `(:>)~\         *
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