Bio-Rad DCode™ Universal Mutation Detection System - Manual (Page 31)

7. Carefully remove air bubbles from the LO syringe by turning the syringe upside down
(plunger cap towards the bench) and gently tapping the syringe. Push the gel solution to
the end of the tubing. Do not push it out of the tubing as loss of solution will disturb the
volume required to cast the desired gel.
Note: The gel solution volume should be greater than the amount set on the volume adjustment
lever. For example, if the indicator setting is set at 14.5, the syringe should contain 15 ml of
solution. This extra solution is needed to deliver the correct amount for casting.
8. Place the LO syringe into the gradient delivery system syringe holder (LO density side) by
holding the syringe by the plunger and inserting the lever attachment screw into the lever
groove. Do not handle the syringe. It will dispense the gel solution out of the syringe. Casting
a parallel gel is referred to as a top filling method, so place the LO syringe on the correct
side of the gradient system.
9. Carefully remove the air bubbles from the HI syringe by turning the syringe upside down
(plunger cap towards the bench) and gently tapping the syringe. Push the solution to the
end of the tubing. Do not push it out of the tubing as loss of solution will disturb the volume
required to cast the desired gel.
10. Place the HI syringe into the gradient delivery system syringe holder (HI density side) by
holding the syringe by the plunger and inserting the lever attachment screw into the lever.
Do not handle the syringe. It will dispense the gel solution out of the syringe.
11. Slide the tubing from the low density syringe over one end on the Y-fitting. Do the same
for the high density syringe.
12. Attach a 19 gauge needle to the coupling. Hold the beveled side of the needle at the
top-center of the gel sandwich and cast (Figure 4.13). For convenience, the needle can
be taped in place.
Fig. 4.13. Casting a parallel gradient gel.
13. Rotate the cam wheel slowly and steadily to deliver the gel solution. It is important to cast
the gel solution at a steady pace to avoid any disturbances between the gel solutions
within the gel sandwich.
14. Carefully insert the comb to the desired well depth and straighten. Let the gel polymerize
for about 60 minutes.
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