Problems with protein extraction with Trizol - (May/17/2006 )

Hi everyone,

I'm trying to extract both RNA and proteins from cultures cells. While the RNA extraction works very well and I can't get any protein.
The problem is when I centrifuge after the ethanol resuspension, the pellet makes clogs and is impossible to redissolve into the guanidine hydrochloride and eventually, I can do nothing with that but throw it all away.
Beside, I make my 0.3M guanidine hydrochloride into 95% ethanol each time I have to isolate proteins and I've never been able to get a clear solution. I always have a white light cloud impossible to dissolve even after heating or stirring for a whole day...

Have anyone already met these problems ? How can I resolve them ?

Thanks

David

there is a special reagent for protein extraction which should be ordered separately from trizol.
Anyway, i didn't like this method, and switched to basical one : separate cells in 2parts, extracting protein or RNA.
But recently, macherey nagel brings a column based RNA extraction kit. see new product forum for that.