Hoefer SE400 User Manual
Page 36
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p28
problem/possible cause
remedy
Poor band resolution (continued)
Sample preparation
Store sample on ice before it is denatured.
Dialyze or desalt the sample.
Heat samples in SDS sample buffer for no more than
1–2 min at 100 °C to improve dissociation of subunits.
Store on ice after heating.
Adjust the sample volume or concentration.
Add more mercaptoethanol or dithiothreitol; check sample
treatment.
Add protease inhibitors such as PMSF if necessary to prevent
proteolytic degradation of sample.
Increase glycerol or sucrose to increase sample density.
Store samples to be frozen in aliquots to avoid repeated
freeze-thawing. Store at -40 to -80 °C.
Tracking dye does not sharpen
into a concentrated zone in
the stacking gel
Poor stacking
Pour a taller stacking gel. (For best results, allow a stacking-
gel height of 2.5 times the height of the sample in the well.)
Reagent quality
Dispose of outdated acrylamide solutions and use only the
highest grade of acrylamide.
Sample preparation
When preparing samples, avoid using solutions with high salt
concentrations.