cloning into Casper

[Richard Friedman]

In article <47uf3e$oqk at manuel.anu.edu.au>, S. Bartoszewski wrote:

> >myersm at rockvax.rockefeller.edu
> 
> 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.

-- 
-Rich
Friedmrd at post.drexel.edu or rfriedma at astro.temple.edu
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