Adventures in DNA extraction
rapr at MED.PITT.EDU
Fri Jul 8 09:31:39 EST 1994
> Now here's the funny part. Through a series of blunders I discovered
> that substituting either sodium acetate or sodium chloride for
> the sodium citrate in the lysis buffer buggers up the protocol.
> I then get a massive precipitate upon ethanol precipitation, most of
> which will not dissolve in TE. It also inhibits recovery of DNA from
> the pellet, although the quality is not reduced. The stuff looks
> like glycogen, which of course like to co-partiion with DNA and
> precipitates with ethanol. The presence of citrate, but not acetate
> or chloride, causes the glycogen (or whatever it is) to either
> partition into the interface or not precipitate with ethanol.
> Can anyone explain this?
Joe (et. al.): a partial possible explanation hinges on the chelating
properties of citrate, the presence of which may alter the properties
of DNA-Metal, RNA-Metal, Glycogen-Metal, and Junk-Metal complexes in
a way that would give your results. One test of that, if anyone cares,
would be to use acetate or chloride + EDTA in place of citrate. But
if citrate works, who cares?
rapr at med.pitt.edu
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