precipitating proteins w/ ethanol

Richard P. Grant r_grant at see.sig.for.address
Fri Mar 5 09:35:49 EST 1999

In article <36DF1563.BF89D47D at virtu.sar.usf.edu>, Katherine Walstrom
<kwalstro at virtu.sar.usf.edu> wrote:

>I have some dilute protein samples that I need to concentrate and run on
>an SDS-PAGE gel.  I can't find a detailed protocol for precipitating
>proteins, although what I've read suggests that ethanol works well.  I
>want to precipitate all the proteins, not just selectively precipitate
>some of them.  Does anyone have a general protocol for this?


we used to just add 2 - 3 vols of EtOH at -20C, mix well, then place on
dry ice or in the -80 freezer until solid.  Thaw to liquidity, and spin
down hard (depending on volume - 15 mins in a microfuge if in epps, 15
mins as hard as you can in Corex tubes for larger volumes) in a chilled
'fuge (microfuge in cold room was fine).

Depending on the salt concentration you may be better off trying to
lyophilize (is that a verb?) the samples.



Richard P. Grant MA DPhil     |             rgrant at cmtech.co.uk
work: www.cmtech.co.uk        |      home: www.avnet.co.uk/adastra
     -- Good morning.  How may I patronize and annoy you? --

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