Ethidium bromide is a substance used in electrophoresis for DNA analysis. It binds to DNA and illuminates under UV light and allows for the DNA in a sample to be detected. The ability to bind to DNA means that it can be hazardous to persons handling the substance, as it also binds to DNA in the human body and may cause heritable genetic damage (mutagenicity class 1 or 2).
Ethidium bromide should as far as possible be phased out.
The content of ethidium bromide in the gels and solutions that are used are considered to be so low that the composite products are not classified as mutagenic according to the requirements of the Swedish authorities. Despite this, you should deal gently with ethidium bromide as the level of exposure is not only depends on the amount and concentration, but also on how often you use the chemical and the procedures that exist in the workplace.
Laboratory and service personnel may be exposed to many different substances and the additive effect of multiple exposures is almost always unknown. Ethidium bromide may be absorbed through the skin and nitrile gloves are considered to be a good protection against ethidium bromide.
A written risk assessment should always be carried out before work with ethidium bromide starts.
Alternative to ethidium bromide
Uppsala University and several research groups at Karolinska Institutet have conducted successful substitutions of ethidium bromide.
Different suppliers have suggestions for substitutes for ethidium bromide:
- VWR - Gel Red och Gel Green
- Sigma Aldrich – SYBR Green I och II
- Invitrogen life Technologies – SYBR Safe