Bio-Rad Mini-PROTEAN® 3 Dodeca™ Cell - Manual (Page 8)

2.4 Required Accessories for Cooling
The Mini-PROTEAN 3 Dodeca cell has a cooling coil with quick connect fittings that
must be connected to a refrigerated circulator. The refrigerated circulator must be able
maintain the buffer temperature of 18–20 ºC during electrophoresis
2 . Tubing with 3/8" ID
connects the Dodeca cell to the refrigerated circulator. To connect the Dodeca cell to the
refrigerated circulator,
a. Insert the male fittings (supplied in a separate bag) into the tubing on the refrigerated
circulator inlet and outlet tubing.
b. Connect the male fittings from the refrigerated circulator to the female fittings on the
Mini-PROTEAN 3 Dodeca cell. The cooling coil in the Dodeca cell has no specific
orientation, so it is not important which direction the flow goes.
In addition to the refrigerated circulator, the Dodeca cell should be used with a stir bar and
stir plate.
By using the maximum volume of buffer, the refrigerated circulator, and the stir plate, the
effects of heat on electrophoresis results are minimized.
2 The refrigerated circulator used during development of the Dodeca cell was set to 15 ºC and had a flow rate of 3.8 liters per minute.
Under these conditions and using the maximum volume of buffer, the buffer temperature during electrophoresis was maintained
at 18–20 ºC.
2.5 Running the Gels
Insert the red and black color-coded power cables into the corresponding red and black
jacks of the power supply. Set the power supply to run at 200 V constant for 35 minutes. For
best results, use the PowerPac 200 power supply.
Application note:
The initial current draw for one 1.0 mm Ready Gel precast gel in a Laemmli formulation is
about 50 mA; a Dodeca cell filled with 12 precast gels will draw 600 mA at the start of a run.
The current will drop approximately 50% during the run.
Section 3
Maintenance
Mini-PROTEAN 3 Dodeca cell tank and lid, Rinse thoroughly with distilled water
clamping frames, buffer dam, gel releaser after every use.
Glass plates and combs Wash with a laboratory detergent, then
rinse thoroughly with distilled water.
Glass plates and combs (when more stringent Soak in 10 N KOH for 30 minutes (max.)
cleaning is required) and then rinse thoroughly with distilled
water.
The buffer in the lower tank may be reused up to 10 times. Sodium azide (final concentration
of 0.02%) is recommended to help minimize contamination.
Ultimately the number of times the buffer is used depends on the number of gels run each
time and the conditions at which the runs are performed. (The primary concern is ion
depletion.) Prepare fresh buffer if the following problems appear:
• changes in protein mobility
• decrease in band sharpness
• longer run times
• a band at the bottom of the gel which is difficult or impossible to destain
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