Bio-Rad DCode™ Universal Mutation Detection System - Manual (Page 73)

Fig. 7.5. Pouring a PTT gel.
10. Pour or pipette the gel solution into the sandwich until it covers the wells of the comb.
Straighten the comb to the desired well depth. Add more solution if needed.
11. Allow the gel to polymerize for about 60 minutes. After polymerization, remove the comb
by pulling it straight up slowly and gently.
12. Continue with Section 8 for electrophoresis.
Section 8
Electrophoresis
8.1 Assembling the Upper Buffer Chamber
1. Lay the inner core flat on a bench. Make sure the white U-shaped gasket on the inner core
is seated properly and clear of any particles that may cause leakage, such as residual gel
material.
2. After the gel has polymerized, release the gel sandwich from the casting stand by turning
the camshafts 180°, to the up position, and pulling them outward. Remove the sandwich
and the comb.
Note: To easily visualize the wells when loading the samples, use a permanent marker
to mark the wells.
3. With the short glass plate facing the core, position the gel sandwich so that the locating pins on
the core are fitted into the grooves on the outside surface of the sandwich clamps (Figure 8.1).
The gel sandwich should be positioned at an angle of 20° with the core. Keeping this angle
to a minimum will prevent distortion of the gasket while the sandwich slides into place.
Note: To help insure a good buffer seal, lubricate the entire front of the core gaskets
with water or running buffer prior to attaching the gel sandwich to the core. This will
allow the glass plate sandwich to slide onto the gasket properly.
4. With your fingers below the latch on the core and your thumbs resting on the bottom of the
sandwich clamps, gently push the gel sandwich down onto the core with one simple motion.
You should be able to hear a click. The upper edge of the short inner glass plate should be
seated against the notches of the U-shaped gasket and the tabs of each clamp should be
held securely against the latch assemblies on both sides of the core (Figure 8.1).
69