Removal of CsCl from CsCl-EtBr gradient preps

[WMELCHIOR at NTDOC.NCTNET.GOV]

I don't know about chromosomal preps, but I routinely remove CsCl from plasmid
preps by multiple extractions with 70% EtOH at room temperature.  ("Multiple" 
means a few, depending on the sample size and CsCL concentration.)  This allows 
me to do everything in microfuge tubes.  Once the DNA has been precipitated, it
stays that way, so chilling is not necessary at subsequent extractions.  CsCl
solubility in 70% EtOH is quite temperature-dependent, hence the room temp.    


Bill Melchior
National Center for Toxicological Research
Jefferson, AR  72079
(501) 543-7206

wmelchior at ntdoc.nctnet.gov