Bio-Rad CHEF-DR® III Variable Angle System - Manual (Page 6)

Accessories included:
Variable speed pump 120 V, ground isolated. Flow rate 1 liter/min, typi-
cal
Casting stand 14 cm x 13 cm
Comb 10 well comb and comb holder
Tygon tubing 365 cm
Disposable sample plug mold 50 slot
Yeast DNA Standard S. cerevisiae YNN295, 2 plugs
Chromosomal grade agarose 5 grams
Pulsed field certified agarose 5 grams
Leveling bubble 1
Fuses 0.5 Amp Fast Blow, 2 spares
Manual 1
Screened cap 1
Cooling Module (Optional):
Weight 14 kg
Construction Aluminum
Dimensions 42 cm long x 23 cm wide x 24 cm high
Cooling capacity 75 watts of input power at 14 °C
Operating range 5 °C–25 °C
Total System Weight 41.7 kg
Note: This equipment complies with the limits for a Class A digital device, pursuant to Part
15 of the FCC rules. These limits provide reasonable protection against harmful interference
when the equipment is operated in a commercial environment. This equipment generates,
uses, and can radiate, radio frequency energy and, if not installed and used in accordance with
the instruction manual, may cause harmful interference to radio communications. Operation
of this equipment in a residential area is likely to cause harmful interference, and the user
will be required to correct the interference at his own expense.
1.4 Description of Major Components
Power Module
The Power Module contains the electronics for pulsed field electrophoresis, including a
350 V power supply, the switching functions, and drivers for the 24 electrodes. The drivers
provide clamped homogeneous electric fields in the electrophoresis cell, and maintain them
regardless of the field angle selected. This dynamic regulation feature modulates the poten-
tials so that the proper voltages are maintained regardless of gel size, or fluctuations in buffer
conductivity or temperature. The fused power supply operates with a maximum voltage gra-
dient of 9 V/cm, or 300 V. The lowest gradient is 0.6 V/cm, or 20 V.
Figure 1.1A shows the relative potentials of each electrode pair when the + 60° vector
(indicated by the arrow) is activated. Net field vector is from NW to SE. The highest poten-
tials are along the SE segment of the hexagon. The potentials gradually decline along the
adjacent segments. The NW segment, directly opposite the SE, has 0 potential, represented in
the diagram as negative terminals. When the - 60° angle is activated, the pattern of electric
charges is as shown in Figure 1.1B. Together, the two pulses result in a 120° included field
angle. Other angles will result in values for the relative electrode potentials, according to pre-
determined values.
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