Bio-Rad DCode™ Universal Mutation Detection System - Manual (Page 76)

2. For TTGE runs, set the desired final temperature and run the gel at 130 volts.
Note: The voltage should not exceed 150 V for TTGE runs, electrophoretic heating may
affect the temperature gradient.
Optional: If your power supply has a built-in timer, set the power supply timer to the
desired run time.
3. The run time should be determined empirically for each fragment being analyzed. As a
reference during electrophoresis, two marker dyes in the 2x gel loading dye can be used
to determine when to stop a DGGE and CDGE run. The dyes are bromophenol blue (dark
blue) and Xylene cyanol (light blue). For a TTGE run, the run time is dependent on the
temperature ramp rate. Refer to Section 4.3 for determining TTGE run conditions.
SSCP Gels
1. Run the gel at 20–40 W constant power for 2–6 hours or until desired resolution is achieved.
The run time should be determined empirically for each fragment being analyzed.
Note: Electrophoresis runs at high power settings (30–40 W) may generate gel heating
which causes the “smiling effect” (bands curve upward at both sides of the gel).
2. As a reference during electrophoresis, two marker dyes in the 2x SSCP gel loading dye can
be used to determine when to stop a run. The dyes are bromophenol blue (dark blue) and
Xylene cyanol (light blue).
Optional: When using radioactive samples, the pump may be turned off during
electrophoresis to reduce radioactive contamination.
3. Apply power to the DCode system and begin electrophoresis. As a precaution, always
set the voltage, current, and power limits when possible.
Heteroduplex and CSGE Gels
1. For heteroduplex analysis and CSGE, run the gel at 100 volts for 16–20 hours. The run
time should be determined empirically for each fragment being analyzed. CSGE gels
typically run between 1–2 mAmps. Check to insure the power supply you are using does
not shut off when the current is below 2 mAmps.
2. Begin electrophoresis. As a precaution, always set voltage, current, and power limits
when possible.
Note: The DCode system temperature control module is off for Heteroduplex and CSGE runs.
PTT Gels
1. It is recommended that gels be run under constant current conditions. For 1.0 mm thick
gels, run at 25–35 mAmps/gel for 45 minutes, then increase the current to 40–50
mAmps/gel. Run times are typically between 3 and 5 hours. Under constant current
conditions, voltage will gradually increase during the run.
Optional: When using radioactive samples, the pump should be turned off during
electrophoresis to reduce radioactive contamination.
2. Begin electrophoresis. As a precaution, always set voltage, current, and power limits
when possible.
Note: The DCode system temperature control module is off for PTT runs.
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