Re: [ccp4bb] Shredded E coli pellets

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CCP4bb <-- 1999 <-- November 1999 <-- 30 November 1999

Previous message:
Subject: Re: Shredded E coli pellets
From: Jacob Keller j-keller2 {- at -} MD {- dot -} NORTHWESTERN {- dot -} EDU
Date: 2009-07-02

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Subject: Re: Shredded E coli pellets
From: Paul Leonard leonard {- at -} CABM {- dot -} RUTGERS {- dot -} EDU
Date: 2009-07-02

Subject: Re: Shredded E coli pellets
From: "Mark J {- dot -} van Raaij" mark {- dot -} vanraaij {- at -} USC {- dot -} ES
Date: 2009-07-02

Dear Jacob,
In my hands, different strains of E. coli appear to behave differently
- I found BL21(DE3) needing harder centrifugation than JM109(DE3) to
get a good pellet. And BL21 lysing partially when doing osmotic shock
extraction of a periplasmically expressed protein - while XL1Blue
behaved well.
Although - thinking about the other comment - perhaps I had an
infection with a phage to which BL21 was sensitive but the others not?
Mark

Quoting Jacob Keller :

> Dear crystallographers,
>
> I recently expressed some new constructs, and found after my usual
> expression protocol that the cell pellets were not compacted at the
> bottom corner of the bottles us usual, but were instead smeared as a
> film on the side, and further, were somewhat clumpy, like clots, and
> with a smaller pellet in the usual location. The centrifugation was
> exactly as usual. I noticed that there was also a bit more foam in the
> medium than usual, but I am not convinced that this was the issue,
> although it might be a symptom. My suspicion is that the constructs are
> lethal and cause cell lysis, but I am not sure. Has anybody seen this
> phenomenon before, and gotten to the bottom of it?
>
> Jacob Keller
>
> *******************************************
> Jacob Pearson Keller
> Northwestern University
> Medical Scientist Training Program
> Dallos Laboratory
> F. Searle 1-240
> 2240 Campus Drive
> Evanston IL 60208
> lab: 847.491.2438
> cel: 773.608.9185
> email: j-keller2@northwestern.edu
> *******************************************

CCP4bb navigation

CCP4bb <-- 1999 <-- November 1999 <-- 30 November 1999

Previous message:
Subject: Re: Shredded E coli pellets
From: Jacob Keller j-keller2 {- at -} MD {- dot -} NORTHWESTERN {- dot -} EDU
Date: 2009-07-02

Next message:
Subject: Re: Shredded E coli pellets
From: Paul Leonard leonard {- at -} CABM {- dot -} RUTGERS {- dot -} EDU
Date: 2009-07-02