(Original 1879, Revised January 1994)
Copyright 1994, Idea Scientific
The Silly Putty clay provided can be used to seal the apparatus. This is done by rolling a 12 inch (30 cm) long rod of silly putty between the fingers and a benchtop. Then, take the rod of silly putty and push it into the three sides of the frontpiece to seal it in place. Leaks usually occur at the two bottom corners so push the clay in well there. (The frontpiece can be sealed with 1.5% agarose but one must be very careful not to jar the apparatus if agarose is used.) Now pour the gel formulation into the sandwiches. Most scientists leave about a 2 cm space at the top of the gels for a comb and stacking gel. Overlayer each gel with 150 microliters of n-Butanol or other overlayer. Allow the gels to set. The best gels will be obtained if the polymerization time is longer than 10 minutes.
The RALWAX 2 provided with the apparatus can also be used for sealing. It is a wax with a melting point of 50 degrees C which can be poured around the frontpiece to give an effective seal. After use it can be scraped from the apparatus for re-use. The low temperature metling point gives easy apparatus clean-up, as the wax will wash away under a hot-water tap. Additional RALWAX 2 can be ordered from Accurate Chemical Co. (phone number 516-333-2221).
After polymerization, remove the gels individually by prying them out with a single-edge razor blade. The drop of water used between the glass plates during the set-up keeps the acrylamide from getting between the glass plates, making separation easier. These gels can be stored several weeks if they are in a humid environment. Zipper-type plastic bags work well for storage. Some scientists store the gels above the surface of a water-filled tray. Remarkably, SDS gels can be stored in the refrigerator without percipitation of the SDS. (Note: Be careful not to disloge the side spacers when handling the gels.)
Prepare a separating gel for use by copiously rinsing then n-Butanol overlay off of the gel, then seal it into the upper reservoir of the MINI-SLAB. Cast the stacking gel in the uppper reservior as it will seal the side spacers if they were dislodged in handling.
Idea Scientific Company
Minneapolis, MN 55414