Bio-Rad CHEF Mapper® XA System - Manual (Page 49)

5. Carefully remove the comb holder and comb. It is sometimes helpful to rock the holder
back and forth slightly during removal. Sample plugs can be added to the wells while the
gel remains in the casting stand.
Compositions of Buffer Stock Concentrates
10x TBE Buffer:
108 g Tris base
(161-0733) 55 g boric acid
40 ml 0.5 M EDTA, pH 8.0
50x TAE Buffer: 242 g Tris base
(161 -0743) 57.1 ml glacial acetic acid
100 ml 0.5 M EDTA, pH 8.0
Fig. 8.1. The CHEF Mapper casting stand, comb holder, and disposable plug molds.
8.2 Buffer Circulation and Temperature
Level the CHEF Mapper electrophoresis chamber by adjusting the leveling screws. Place
the leveling bubble at the center of the chamber. Place the casting frame in the chamber. Pour
2.2 liters of buffer into the chamber. Switch on the CHEF Mapper power, then switch on the
variable speed pump. Circulate at ~1 L/min (a setting of ~70 on the pump regulator). Maintain
the flow rate at the maximum setting that does not disturb the gel. Allow the buffer to equi-
librate to the desired temperature. We recommend 14 °C buffer temperature in chamber. The
temperature can be read by pressing ACTUAL TEMP on the Cooling Module panel. The
buffer can be chilled by the following methods:
• Attach the Cooling Module (see Cooling Module manual).
• Coil pump tubing into a temperature-controlled water bath with the temperature set so
that the buffer temperature in the gel chamber is 14 °C.
• Coil pump tubing into a bucket containing ice water, and measure the temperature in the gel
chamber. Continue to add ice or warm water to maintain the desired temperature during
the run.
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