cloning into Casper

S.Bartoszewski S.Bartoszewski
Wed Nov 29 00:45:40 EST 1995

In article <friedmrd-1711950953010001 at n1-2-210.macip.drexel.e> friedmrd at (Richard Friedman) writes:
>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.
I am using pW8 [Klemenz, Weber & Gehring (1987) NAR 15; 3947-3959].  It is not
a derivative of pCaSpeR, but was constructed independently in a very similar
way.  I don't know about using JM109, I would check whether it is recA.  

E-mail: slawek at

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