"Dr Koen A.L. De Smet" <k.desmet at ic.ac.uk> wrote:
>packard at kersur.net wrote:
>>>> >Viraj Master wrote:
>> >>
>> >> Hello all,
>> >>
>> >> I am using the Qiagen pQE series of vectors to express proteins. There
>> >> are two buffers which I use a lot, Buffer B and Buffer C.
>> >>
>> >> These contain:
>> >> 8M urea
>> >> 0.1M NaH2PO4
>> >> 0.01M Tris
>> >>
>> >> Buffer B is at pH=8
>> >> Buffer C is at pH=6.3
>> >>
>> >> I have been told that I must make these buffers up **fresh** each time
>> >> prior to use. I would like to be able to prepare batches of these
>> >> buffers and store them. Does anybody know whether this can be done and
>> >> not affect the protein prep? If so, are they stored in the cold, or at
>> >> room temp? For how long can they be stored?
>> >>
>> >> Many thanks,
>> >>
>> >> Viraj
>> >>
>> >> Viraj Master PhD
>> >> Dept of Organismal Biology
>> >> University of Chicago
>> >
>> >
>The reason why they cannot be used after long storage is because the
>pH is not stable. Maybe I am just lazy, but I keep these buffers at
>room temperature for several weeks and when I want to use them again,
>I simply adjust the pH. This seems to work.
>_______________________________________________________________
>> Dr Koen A.L. De Smet
> Research Fellow
> Department of Medical Microbiology
> Imperial College Medical School at St Mary's
> Norfolk Place
> London W2 1PG
> Great Britain
>> Tel: (+44)-(0)171-594 3946
> Fax: (+44)-(0)171-262-6299
> Email: k.desmet at sm.ic.ac.uk>http://www.sm.ic.ac.uk/medmicro/home.htm>_______________________________________________________________
>>"If we knew what it was we were doing,
> it would not be called research, would it?". -- A.Einstein
>_______________________________________________________________
Yeah, I agree with this. The pH changes due to the dissociation of urea,
so I keep my buffers for weeks and just adjust the pH just before use.
Cheers,
Joe Boutell.
