Dissolve my pellet, please!

Christoph.Lorra at urz.uni-heidelberg.de Christoph.Lorra at urz.uni-heidelberg.de
Thu Feb 6 17:24:13 EST 1997


In <32F7A202.212F at codon.nih.gov>, jberke at CODON.NIH.GOV (Josh Berke) writes:
>Hi: 
>
>I have pellets of cDNA that just do NOT want to dissolve.
>
>I performed a phenol:chloroform extraction followed by
>a phenol:chloro:IAA extraction. I precipitated the DNA using
>4M NH40Ac and 95% ethanol, with 20min room temp spin at 14,000.
>This was done in a siliconized 0.5ml tube (from Ambion). After
>removing the supernatant I could see the pellet; the cDNA is also
>radiolabelled so I can keep track of it....

Hi 

this sounds indeed a bit difficult. 
Because you have vortexed the sample you might have destroyed it anyhow. 
If not I would try to wash it again several times with 70 % ethanol and afterwards 
try to resuspend it in a bigger volume of TE ( make sure the pH is around 8 ). 
A high pH might help because of the salt you used. 
Afterwards you can precipitate it again with  1/10 volume 3 M NaAcetat pH 5 
and 3 volume EtOH, wash 2 times with 70 % EtOH and disolve in TE pH 7.9 or 8.  

Hope this will help

Ciao	Christoph



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