Bio-Rad Model 225 Tube Gel Casting Stand - Manual (Page 11)

4. After adding the catalysts, fill a syringe with monomer solution, and attach a
needle.
Caution: Wear gloves when handling acrylamide!
5. Insert the needle into the casting tube so that the point is below the tops of the
capillary gel tubes. Deliver monomer solution so that the gel tubes fill from the
bottom. Some bubbles will remain, but most bubbles will be between the tubes,
rather than in them. Cast the gels to the top of the tubes. Tap the casting tube to
remove trapped bubbles. Fix the casting tube in the vertical position with the
clamp and ring stand, or place the casting tube in the tube rack. With the casting
tube vertical, allow the monomer to polymerize. This process should take
approximately one hour.
6. After polymerization, remove the Parafilm laboratory film slowly from the
bottom of the casting tube, and push the batch of capillary tubes out of the
casting tube from the top. Be careful not to introduce bubbles into the bottom
of the tubes.
7. Wipe the extra acrylamide off the tubes. Do this carefully, to avoid introducing air
bubbles into the top or bottom of the tubes. If a tube contains any bubbles it must be
discarded, because the bubble breaks the electrical circuit, and electrofocusing
will not occur.
8. Attach the blue stripped end of the tubes to the sample reservoirs with the flexible
tubing connectors.
Note: The tubing connectors must be replaced after each use. Repeated use will
cause the connectors to become distorted so they no longer fit snugly over the
ends of the capillary tubes or the sample reservoirs. Failure to replace worn tubing
connectors can result in upper buffer leaks and potential damage to the tube
adaptor.
9. Rinse the bottoms of the tubes with lower buffer.
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