precipitation of oligos

rupp at rupp at
Wed Mar 31 07:43:52 EST 1993

In article <01GWDRYK1UZM001MA9 at>, BISHOP at MSVAX.MSSM.EDU ("DAVID F. BISHOP") writes:
> Thomas RUPP writes:
>>a) why does nobody mention the easiest and fastest way, without any
>>salts beeing involved : the n-butanol precipitation of oligos ??
> However, I would dearly love to save our vacuum pumps from all this ammonia
> vapor.  Does anyone have experience with using smaller volumes of butanol
> or with centrifugation at lower speeds (but not for 2 hr)?
> David Bishop                             | EMail:Internet:Bishop at

Hi David,

we also using an up-scale of this method in our lab:

Add 25ml n-butanol to 2ml ammonia solution in an 50ml Falcon tube (or
equivalent) and spin at about 5000 rpm in a suitable centrifuge for 
about 20 min.

If you use smaller volumes of n-butanol the two phases won't homogenize
properly during the vortex step!!

Or spin it down in a Sorvall centrifuge (the one used for large scale plasmid
preps) using a SS34 rotor with the 36ml tubes for 20 min at 20000 rpm!


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