Drying Polyacrylamide Gels - Cheap!

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Drying Polyacrylamide Gels - Cheap!

You must first have a pair of plexiglas® (Lucite®) plastic frames as shown at the left. Make as many pairs as you think you will have gels to dry at any one time. You must also have ONE center piece that very loosely fits within the opening of the frames. Design the frame such that it is about 4 cm in both dimensions larger than the gel to be dried. By far the best way to glue plexiglas together is by "welding" it using chloroform: Weld the two pieces together. The next day, a good weld will be as if the plastic were all one continuous piece. / The clamps can be purchased in a stationery or secretarial supply store.

TO USE: (These steps take a total of about 15 seconds to do:)

  1. Place a pan to catch drippings on the floor next to your lab bench.
  2. Place one of the frames on a countertop, and place the center inside of the frame.
  3. Slop your drying solution onto all the upper surfaces of the frame and center piece.
  4. Soak your cellophane (semipermiable membrane) in the drying agent.
  5. Lift the wet cellophane out of its container and lay it out upon the frame so that only a half of it is lying on the frame and center piece. Work out any trapped bubbles from between the cellophane and the plastic.
  6. Slop some more liquid onto the cellophane.
  7. Position your gel so that it is in the center of the frame. Work out any trapped bubbles between the gel and the cellophane
  8. Slop some more liquid onto the gel.
  9. Lift up the outer edge of the protruding half of the cellophane and slowly fold it over the gel such that the excess liquid helps push away bubbles as the cellophane is lowered upon the gel. Try not to have ANY trapped bubbles on or AROUND the gel.
  10. Once the upper layer of cellophane is in place, set the second piece of framing on top.
  11. (Here comes a very tricky part:) Pull - WITHOUT LIFTING - the "sandwich" toward you so that its near edge is fully off the tabletop. SLOWLY place a large metal spring clamp onto each of the two corners that are out over the tabletop.
  12. SLOWLY lift the frame up just enough to be able to rotate the sandwich 180° to protrude the remaining two corners over the edge of the tabletop. And slowly put on two more clamps.
  13. Lift the sandwich horizontally allowing the center piece to fall away, and slowly, slowly rotate into the vertical. If you do it too fast the gel will shift in the trapped liquid, but if you do it slowly, the trapped liquid will be able to flow to the bottom without moving the gel out of position.
  14. Still holding the gel vertically, remove one of the corner clamps and work a fingernail between the plastic to allow the excess liquid to flow out into your reservoir.
  15. Replace the clamp
  16. The clamps can act as legs: allow the gel to dry vertically.
  17. WARNING! Some cellophanes are too thin, and will shrink and implode as the gels dry. What you need to do in that case, after 4 or 5 hours of drying, is to remove one clamp at a time, work your fingernail between the plastic and allow relaxation of the tension. Hopefully, by the next morning, you will not find the system imploded.
  18. The gels must be VERY dry before proceeding.
  19. Remove the clamps, remove the plastic frames and IMMEDIATELY cut away the cellophane that had been pinched between the frames. This portion of the cellophane will still be damp and if not cut away immediately it will dry and shrink and crinkle and deform the inner portion.
  20. You may photocopy the final product using the copier's lightest setting (polyacrylamide is rather photodense at whatever wavelengths are used by the copiers).

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