Wear disposable gloves when staining gels. Gloves are important when working with intercalating dyes, which are potential mutagens.
- Remove the gel from the apparatus and transfer the gel to a small tray. Cover the gel with deionized water. Add 5 μL of EtBr solution (10 mg/mL) to the tray. What is the approximate concentration of EtBr in the staining solution?
- Place the tray on a rocking platform and rock gently for 20-30 minutes.
- Drain the EtBr solution in to the appropriate waste container in the fume hood.
- Cover the gel with deionized water and rock gently for 1 minute.
- With a spatula, carefully place the gel on the transilluminator and close the cover to the Gel- Logic apparatus. (Drain the wash solution into the waste container.)
- Turn on the transilluminator light and photograph the gel according to the posted instructions. Turn off the transilluminator immediately after you photograph the gel. Save the picture and email a copy to yourself. (If no bands are apparent, the staining can be repeated for a longer period of time.)
- Open the door of the GelLogic apparatus. Use the spatula to transfer the gel to a waste con- tainer set up for EtBr-stained gels.
- Determine the approximate length of the DNA molecules in your samples by comparing their migration to that of the standards. Are the sizes consistent with your expectations?