EMSA/band shift assay with RNA probes
jochen at iigb.na.cnr.it
Tue Jul 24 11:36:26 EST 2001
I'm trying to get a band shift with cytoplasmic and nuclear extracts
from HeLa cells using RNA probes for binding. Actually I'm getting a
band shift, but the problem is that there are two bands, same for
each kind of extract, but they are appearing and disappearing in an
irregular manner, meaning one time i have two bands in the nuclear
assay and another time just one. for the cytoplasmic extracts it's
even more confusing because i get either band or nothing.
The upper band has the height of the undigested probe, but the the
digestion control for the rnase was ok, so i didn't suppose it might
be the undigested probe, but now i get some doubts on that.
Eventually that would mean that the upper band is an artefact, and
actually i wasn't able to do a competition on it yet, but for the
lower band there was a competition.
So i would be very pleased if someone could tell me if the band with
height of the probe might be the undigested probe and if different
concentrations of protein and/or probe might change the resulting
Thanks a lot in advance,
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