Bio-Rad DCode™ Universal Mutation Detection System - Manual (Page 39)

6. Align the plates and spacers by simultaneously pushing inward on both clamps at the locating
arrows while pushing down on the spacers with your thumbs. Tighten both clamps just enough
to hold the sandwich in place. Pushing inward on both clamps at the locating arrows will insure
that the spacers and glass plates are flush against the sides of the clamps (Figure 4.19).
Fig. 4.19. Aligning spacers in the sandwich assembly.
7. Remove the alignment card. Remove the sandwich assembly from the casting stand and
check that the plates and spacers are flush at the bottom. If they are not flush, realign the
sandwich and spacers for a good seal (Repeat steps 5–7).
8. When a good alignment and seal are obtained, tighten the clamp screws until it is finger-tight.
Casting CDGE Gels
1. Place the gray sponge onto the front casting slot. The camshafts on the casting stand should
have the handles pointing up and pulled out. Place the sandwich assembly (16 x 16 cm) on
the sponge with the shorter plate facing forward. When the sandwich is placed
correctly, press down on it and turn the handles of the camshaft down so that the cams lock
the sandwich in place.
2. Into a 50 ml tube, add the required amounts of low density and high density solutions
required for the desired denaturant percentage (see CDGE calculation, Section 4.2). Add
a final concentration of 0.09% (v/v) each of ammonium persulfate and TEMED solutions.
Cap the tube and mix.
3. Insert a comb in the gel sandwich and tilt it so the teeth are at a slight angle. This will prevent
air from being trapped under the comb teeth when pouring the gel solution (Figure 4.20).
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