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Re: [ccp4bb] Bacterial induction at 18C
 

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CCP4bb <-- 2008 <-- April 2008 <-- 30 April 2008
Previous message:
Subject: Re: Bacterial induction at 18C
From: Christopher Law chrisjlaw {- at -} GMAIL {- dot -} COM
Date: 2008-04-30 		Next message:
Subject: Re: Bacterial induction at 18C
From: rabcri {- at -} CID {- dot -} CSIC {- dot -} ES rabcri {- at -} CID {- dot -} CSIC {- dot -} ES
Date: 2008-04-30


Subject: Re: Bacterial induction at 18C
From: Guenter Fritz guenter {- dot -} fritz {- at -} UNI-KONSTANZ {- dot -} DE
Date: 2008-04-30
Raji,

>
> I am working with E. coli cells co-transformed with two plasmids and I find that my cells lyse
> following overnight inductions at 18C.
Sounds more like a phage contamination. The phage becomes active as soon
as the cells "energy level" decreases, e.g upon induction. We had once
the same trouble. If it is a phage, autoclave everything and clean the
lab thoroughly.
> I suspect (among many things) that Ampicillin+
> Chloramphenicol+ Kanamycin in the medium may be the source of my woes.
>
> My colleagues have suggested growing cultures at 18C, say for 4-6h instead. Has anyone had
> reasonable protein expression levels by inducing cultures at 18C for 6h? From what I understand, the
> E. coli doubling time is manyfold longer than at 37C. But I thought I'd ask.
>
Rule of the thumb is the Q10 rule, or in the case of e.coli it is a Q7
rule. Doubling decreases twofold when temperature eis decreased by 7 deg C.

Godd luck,
Guenter
> I am already playing with lowering and/or doing away with the antibiotics.
>
> Any suggestions wrt 18C? The protein is insoluble at 30C.
>
> Thanks.
> Raji
>

--
***********************************

Priv.Doz.Dr. Guenter Fritz
Fachbereich Biologie
Sektion Naturwissenschaften
Universitaet Konstanz
http://www.biologie.uni-konstanz.de/fritz

Universitaetsstrasse 10
Postfach M665
D-78457 Konstanz

e-mail: Guenter.Fritz@uni-konstanz.de

Tel. Office: +49-(0)7531 88 3205
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CCP4bb navigation

CCP4bb <-- 2008 <-- April 2008 <-- 30 April 2008
Previous message:
Subject: Re: Bacterial induction at 18C
From: Christopher Law chrisjlaw {- at -} GMAIL {- dot -} COM
Date: 2008-04-30 		Next message:
Subject: Re: Bacterial induction at 18C
From: rabcri {- at -} CID {- dot -} CSIC {- dot -} ES rabcri {- at -} CID {- dot -} CSIC {- dot -} ES
Date: 2008-04-30


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