Bio-Rad CHEF Mapper® XA System - Manual (Page 11)

2.2 Operation
This section describes general operation. See Section 7 and 8 for sample preparation, gel
casting, gel running, and staining.
1. Pour 2.2 liters of buffer into the electrophoresis chamber.
2. Insert the casting frame into the positioning holes in the electrophoresis chamber. There
are two sets of three positioning holes, depending on the gel size. Do not insert gel stops
in the positioning holes at the top of the gel; they will interfere with the electric field and
cause distortions.
3. Place the gel on the frame. The buffer level inside the frame should be approximately
1–2 mm above the surface of the gel.
4. Turn on the variable speed pump. Maintain a flow rate that is strong enough to keep the
gel inside the frame, but not so strong that it causes the gel to float.
5. Close the lid of the electrophoresis chamber.
6. Check the buffer temperature in the electrophoresis chamber by pressing ACTUAL TEMP
on the Cooling Module panel. Make temperature adjustments at the cooler if necessary.
7. Set the run parameters for the electrophoresis run, following the instructions in Section 4.
If using the auto algorithm, see Section 5.
8. Press START RUN to begin electrophoresis. Gas bubbles should begin to form at the
electrodes. At low field strengths, gas bubble formation is very difficult to see. Check
the current display on the running screen. There should be a finite current reading. If the
current is 0, see Section 11, Troubleshooting.
Section 3
CHEF Mapper System Tutorial
The tutorial demonstrates the five methods in which run parameters can be entered into
the CHEF Mapper system. The entire tutorial will take about 20 minutes, and will familiarize
you with how the run parameters are entered for each method. You should have the unit
completely set up, including the gel chamber with the lid secured (see Section 2).
Turn the instrument on with the power switch at the lower left. The AC power lamp will
light. You will see the current ROM version, followed by the message Welcome to the CHEF
Mapper system. Please enter a command. The tutorial will concentrate on the top panel of
keys (Figure 3.1). For more detailed explanations of the methods described here, refer to
Sections 4–6. Words in bold are as they appear on the CHEF Mapper display, and capitalized
words refer to keys on the control panel.
Fig 3.1. Top panel of keys on the CHEF Mapper system.
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