Isolation of nuclei from mammalian cells - (Apr/16/2002 )

Hi...

I'm trying to isolate nuclei from HeLa cells for nuclear run-off assays.  Using my current protocol, the nuclei would lyse (becomes extremely viscous) when I add the transcription buffer for the assay.   Does anyone have a successful protocol or tips?

I basically know 2 different methods for isolating nuclei. a) Trition-X-100: this has been published in MacGillivray et a., B.B.A. 1972 (277), 384 - 402.
b) Citric acid: this one I have as a brief methods sheet which I can send. Please send your address if you want this.