Bio-Rad Sequi-Gen GT Sequencing Cell - Manual (Page 22)

2. Load samples on the gel (see Table 2.1 for recommended sample loading volumes for
all Bio-Rad combs).
• Samples may be applied with a 5 µl Hamilton syringe, or a pipettor fitted with gel
loading tips (use Bio-Rad catalog number 223-9911).
• Syringe loading requires rinsing the needle between samples.
• Be sure to reconnect the upper safety cover before turning on the power supply.
Note: Sample loading is the key to high resolution gels.
• Rinse wells thoroughly before sample loading begins.
• Deposit samples directly on the gel surface.
• Electrophorese the samples into the gel soon after loading (every 4 lane sets) to reduce
sample diffusion and enhance band resolution.
4.6 Gel Electrophoresis
1. Make sure both safety covers are in place.
• Apply the voltage by pressing the Start or Run button on the power supply.
• Verify that current is flowing (note bubbles forming at the cathode wire in the IPC),
and that all electrical connections are solid.
Running the gel with constant power (watts) will result in a constant gel temperature
during the run and reproducible gel electrophoresis.
Power conditions for DNA sequencing gels are usually dictated by gel running temper-
ature. Run sequencing gels at 50 °C for best results. Refer to the following table for
typical power (watts) settings that result in 50 °C runs.
These settings are only guidelines–optimal settings for gels should be determined empir-
ically. Use a temperature indicator (one is included with this unit) to monitor running
temperatures. If the temperature goes above 55 °C, reduce the power output of the supply.
Alternatively, use a power supply with temperature control functions (PowerPac 3000
with temperature probe) to monitor and control gel temperature.
Table 4.3 Approximate Power (Watts) Settings for Operating Sequi-Gen GT Cells
Sequi-Gen GT Gel Recommended
Cell Size Thickness Power Setting
21 x 40 cm 0.25 mm 35-45 W
21 x 40 cm 0.40 mm 40-50 W
21 x 40 cm 0.75 mm 45-55 W
21 x 40 cm 0.25-0.75 mm wedge 45-55 W
21 x 40 cm 0.4-1.2 mm wedge 45-55 W
21 x 50 cm 0.25 mm 45-55 W
21 x 50 cm 0.40 mm 50-60 W
21 x 50 cm 0.75 mm 55-65 W
21 x 50 cm 0.25-0.75 mm wedge 55-65 W
21 x 50 cm 0.4-1.2 mm wedge 55-65 W
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