This is a cached page for the URL ( To see the most recent version of this page, please click here.
Protocol Online is not affiliated with the authors of this page nor responsible for its content.
About Cache



Decontamination of Ethidium Bromide Solutions and Surfaces

WARNING: EtBr is toxic and mutagenic. Hypophosphorus and its solutions are\corrosive. Decontamination solution gives off a small amount of nitrogendioxide, a toxic gas, when initially mixed.

Laboratory Safety Practices and Equipment:

- Prepare decontamination solution in the fume hood.
- Wear two layers of gloves, lab coat and safety glasses.
- Turn off electrical equipment before decontamination.

Preparation of Decontamination Solution:

Prepare fresh solution on day of use. Add hypophosphorus acid to an aqueous solution of sodium nitrite:

  1 litre 2 litres 3 litres
Sodium nitrite 13.6g 27.2g 40.8g
Hypophosphorus acid 67ml 134ml 200ml

Decontamination of EtBr Waste:

- Procedure has been validated for EtBr solutions of less than 0.5mg/ml in water, TBE buffer, MOPS buffer and CsCl gradients. For solutions greater than 0.5 mg/ml, dilute to 0.5 mg/ml with water.
- Liquid waste: Add 1 part decontamination solution to 3 parts EtBr solution (25%).
- Solid waste: Ensure that all waste is submerged in the decontamination solution and in contact with it.
- Mix and hold for 20 hours.
- Neutralise with sodium bicarbonate and discard as non-hazardous aqueous waste for solutions. For solids, seal in plastic bags and discard.


  1. Lunn, G. and Sansone, E.B. (1987) Ethidium bromide: destruction and decontamination of solutions. Anal. Biochem 162:453.
  2. Lunn, G. and Sansone, E.B. (1989) Decontamination of ethidium bromide spills. Appl Ind Hyg 4:234.
Disclaimer: The following set of protocols were contributed by various members of our lab (past and present): Christine Andrews, Fiona Christensen, Neil Della, Ross Dickins, Debbie Donald, Andrew Holloway, Gary Hime, Colin House, Yinling Hu, Rachael Parkinson, Nadia Traficante, Hannah Robertson, Ping Fu and Dennis Wang. Special thanks to Vicki Hammond, Frank Kontgen and Maria Murphy, who contributed many of the ES cell protocols. Sections dealing with Photomicroscopy, Polyclonal and Monoclonal Antibody Production were provided by members of Gerry Rubin's Laboratory (Berkeley). Any comments in the methods (technical errors etc.) E-mail:
David Bowtell PMCI October 1998