Bio-Rad CHEF-DR® III Variable Angle System - Manual (Page 8)

Cooling Module
The Cooling Module is a stand alone, portable refrigerated apparatus specifically for use
with the CHEF-DR III system. The variable speed pump circulates electrophoresis buffer
directly through the unique heat exchanger, which is a tube within a tube. Buffer circulates
through the inner stainless steel tube, while liquid refrigerant circulates through the outer cop-
per tube, resulting in rapid and efficient cooling at a rate of 0.75 °C/minute (from ambient
temperature to 14 °C). The temperature probe in the cell regulates cooling by the Cooling
Module, resulting in precise maintenance of buffer temperature.
The complete CHEF-DR III system is shown in Figure 1.2.
Fig. 1.2. The complete CHEF-DR III chiller system, with chamber, power module, variable speed
pump, and Cooling Module.
Section 2
Operation
2.1 Instrument Setup
Place the CHEF-DR III electrophoresis chamber on a level surface, with the power mod-
ule to the right or on a shelf above. Position the electrophoresis chamber with the two ports
facing you and the lid safety interlock to the rear. If the system includes a Cooling Module,
place it to the left of the chamber. Place the variable speed pump at the rear of the chamber
and connect the plug from the pump to the port labeled PUMP CONNECTOR on the back of
the power module. Level the electrophoresis cell with the leveling feet at each corner by plac-
ing the casting platform in the center of the cell, then placing the leveling bubble (provided)
on the casting platform. Putting the casting platform in the center of the cell will level the gel
with respect to the electrophoresis cell.
5