constant voltage or amperage

bipin k. dalmia dalmiabk at
Mon Sep 15 15:31:27 EST 1997

my .002 cents:

whenever you make up a fresh batch of buffer for an electrophoresis
run, you will never actually exactly reproduce the conductivity (or
ionic strength). so, if the main concern is day-to-day
reproducibility, e.g. if you always run gels for 1 hour and would like
to see the same banding pattern of your MW markers everytime, it is
better to run at constant voltage, because then the change in
resistance (due to small differences in buffer composition and not
pore size as one poster earlier stated), will be compensated by a
change in the current drawn. (of course then the change in current
will lead to a change in temperature which in turn will lead to a
change in resistance......)


Bipin K. Dalmia, Ph.D.
Protein Expression and Purification
Pioneer Hi-Bred International, Inc.
Johnston, Iowa 50131

dalmiabk at

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