We have been having an unsual RNA problem in our lab lately and
since I have never seen this before, I don't quite know what to make of
it. We are harvesting total RNA from rat epithelial cell lines, using the
traditional CsCl ultracentrifugation. But instead of getting a lovely 260
peak and an equally lovely ratio (which we still do get from time to
time!) we are now picking up a very strong peak at 220; sometimes this is
accompanied by a lesser peak at 260, sometimes it is there all by itself.
The yields are pretty good and they look O.K. (not fabulous) on
formaldehyde gels. My question is, what could be causing this absorbance
at 220, why is the 260 there sometimes and sometimes not, and how does
this impact on the quality of my total RNA? We are not doing
phenol/chloroform extractions, so this is not the problem. Any thoughts
anybody out there has would be greatly appreciated.
"Better living through chemistry"