Bio-Rad PROTEAN Plus Dodeca Cell - Manual (Page 16)

Section 5
Troubleshooting Guide
Problem Cause Solution
1. Smile effect– band pattern
a. Center of the gel running a. Improper cooling.
curves upward at both sides hotter than either end The cooling coil and
of the gel refrigerated circulator
MUST be used in order
to maintain buffer
temperature at
approximately 20 ºC.
Measure the buffer
temperature and adjust
the refrigerated
circulator settings.
b. Power conditions are b. Decrease voltage from
excessive 200 V to 150 V or
make sure buffer is
filled to correct level.
c. Plate not greased properly c. Apply an excess amount
causing current leaks. (If of grease along the
using non-hinged cassettes). entire edge of the dry
plate. Do not remove
the plate from the tank
once it is inserted down
into position until the
run is complete. This
could loosen the grease
and cause it to fall out.
2. Frowning effect–band a. The buffer is not a. Check the Buffer
pattern curves downward recirculated properly recirculation set-up
at one or both sides of the and the edges of the gel (see Section 2.3). Make
gel. are getting warmer then sure the black fittings
the middle of the gel. or manifold tubing in
the lid are extending
just past the buffer
level. The black fittings
or manifold tubing can-
not extend too far into
the buffer; otherwise
the buffer at the very
top will not be
recirculated properly.
3. Run takes unusually long a. Ion depletion in running a. Prepare and use fresh
time. buffer buffer.
b. Running buffer too b. Check buffer protocol
concentrated and dilute buffer if
necessary.
4. Changes in protein mobility a. Ion depletion in running a. Prepare and use fresh
or band sharpness. buffer buffer.
b. Gels running too hot. b. Same as #1 solution a
and b.
Problem Cause Solution
14