Avoiding RNase contamination
Some guidelines on how to best avoid RNase contamination.
Common sources of contamination
- Buffers contaminated with microorganisms. (Note that the solutions need not be turbid to be problematic.)
- Pipettors. Keep a separate set of pipettors for RNA use to avoid contamination with RNases. Avoid touching the barrel or metal ejector to the sides of tubes.
- Keep separate a set of pipettors, glassware, plasticware, reagents, electrophoresis apparatus etc. for RNA use only.
- Store solutions in small aliquots and discard each aliquot after use.
- Clean electrophoresis apparatus.
- Wash with detergent solution.
- Rinse in H2O.
- Dry with ethanol.
- Fill with 3% solution of H2O2.
- Incubate 10 mins at room temperature.
- Rinse with DEPC treated H2O.
- Handle chemicals handled with disposable spatulas.
- Whenever possible treat solutions with 0.1% DEPC for 1 hour at 37°C and autoclave 15 mins at 15 psi.
- Bake glassware at 300°C for 4 hours.
- Treat plasticware with RNAseZap or DEPC.
- Use RNase-free disposable tips and tubes. Use sterile forceps to transfer items to racks.
- According to tests run by Ambion, autoclaving H2O is sufficient to remove most (but not all) RNase activity from water.