Gels can be dried using passive evaporation (air-drying) or vacuum drying. Vacuum drying is faster than passive air-drying methods but often results in cracked gels due to the speed of dehydration.
We recommend drying Novex® Pre-Cast gels using passive air-drying methods such as DryEase® Mini-Gel Drying System (see below).
You will need following items:
- DryEase® Mini-Gel Drying System
- Gel-Dry™ Drying Solution (or prepare your own gel drying solution containing 30% methanol and 5% glycerol)
- StainEase® Gel Staining Tray or a round container
- After all staining and destaining steps are complete, wash the destained gel(s) three times for two minutes each time in deionized water (50 ml per mini-gel) on a rotary shaker.
- Decant the water and add fresh Gel-Dry™ Drying Solution (35 ml per mini-gel).
- Equilibrate the gel in the Gel-Dry™ Drying Solution by shaking the gel for 15-20 minutes in the StainEase® Gel Staining Tray or in a round container. Note: Do not equilibrate gels stained with Coomassie® G-250 in the Gel-Dry™ Drying Solution for more than 5 minutes to avoid losing band intensity.
- Cut any rough edges off the gel (including the wells and the gel foot) using the Gel Knife or a razor blade.
- Remove 2 pieces (per gel) of cellophane from the package.
- Immerse one sheet at a time in the Gel-Dry™ Drying Solution. Allow 10 seconds for complete wetting before adding additional sheets. Do not soak the cellophane for more than 2 minutes.
- Place one side of the DryEase® Gel Drying Frame with the corner pin facing up, on the DryEase® Gel Drying Base.
- Center a piece of pre-wetted cellophane from Step 5 over the base/frame combination, so the cellophane lays over the inner edge of the frame.
- Lay the gel on the center of the cellophane sheet making sure no bubbles are trapped between the gel and the cellophane. Add some Gel-Dry™ Drying Solution to the surface of the cellophane, if necessary.
- Carefully lay the second sheet of cellophane over the gel so that no bubbles are trapped between the cellophane and the gel. Add some Gel-Dry™ Drying Solution if necessary. Gently smooth out any wrinkles in the assembly with a gloved hand.
- Align the remaining frame so that its corner pins fit into the appropriate holes on the bottom frame. Push the plastic clamps onto the four edges of the frames.
- Lift the frame assembly from the DryEase® Gel Drying Base and pour off the excess solution from the base.
- Stand the gel dryer assembly upright on a bench top. Be careful to avoid drafts as they can cause an uneven rate of dying which leads to cracking. Drying will take between 12–36 hours depending on humidity and gel thickness.
- When the cellophane is dry to touch, remove the gel/cellophane sandwich from the drying frame. Trim off the excess cellophane.
- Press the dried gel(s) between the pages of a notebook under light pressure for approximately 2 days. Gels will then remain flat for scanning, photography, display, and overhead projection.
General guidelines are provided below to minimize cracking during vacuum drying of gels. For detailed instructions on vacuum drying, follow the manufacturer’s recommendations.
Handle Gels with Care:
Remove the gel from the cassette without breaking or tearing the edges. Small nicks or tears can act as a starting point for cracking. Remove the gel wells and foot off the bottom of the gel with a Gel Knife or a razor blade . Use the StainEase® Staining Tray for staining and destaining gels. This tray is designed to facilitate the solution changing process without handling of gels.
Use a Gel Drying Solution:
We recommend equilibrating the gel in a gel drying solution such as Gel-Dry™ Gel Drying Solution for 10-30 minutes at room temperature with gentle shaking on an orbital shaker before drying the gel. Gel-Dry™ Gel Drying Solution contains a proprietary non-glycerol component to effectively regulate the rate of drying and prevent cracking. The gel drying solutions do not interfere with autoradiography. To prepare your own gel drying solution, prepare a solution containing 30% methanol and 5% glycerol.
Note: Do not incubate gels stained with Coomassie® G-250 in gel drying solution for more than 5 minutes as the bands may fade.
Remove Air Bubbles:
Remove any air bubbles that may be trapped between the paper, gel, and plastic wrap by rolling a small glass pipette over the gel. Use additional gel drying solution to help remove the air bubbles.
Use Proper Gel Dryer Set-up:
Place gel on the gel dryer with the plastic wrap facing up. Use a proper working condition vacuum pump and make sure a tight seal is formed by the vacuum. Dry gels using drying conditions set for polyacrylamide gels which require increasing the temperature to a set value and holding this temperature throughout the drying cycle. The recommended conditions for mini-gels are 80° C for 2 hours.
Ensure Gel is Completely Dry:
The gel will crack if the vacuum seal of the heated gel dryer is broken prior to complete drying of the gel. To ensure the gel is completely dried before releasing the vacuum seal, follow these tips:
- Check the temperature of the gel
- The temperature of the dried gel should be the same as the temperature of the surrounding gel drying surface. If the temperature of the dried gel is cooler, then the gel is not completely dried.
- Check for moisture in the tubing connecting the gel dryer to the vacuum pump
- The gel is not completely dried if there is any residual moisture in the tubing and additional drying time is required.