Ethidium bromide, long used as an inexpensive, sensitive, and stable dye for staining nucleic acids, is a potent mutagen, possible carcinogen and reproductive toxin with significant health risks for researchers. Its waste stream is cumbersome, time consuming and expensive.
SYBR-based and other alternative DNA dyes are considered to be safe for both the user and the environment. The dyes are noncytotoxic and nonmutagenic at concentrations well above the working concentrations used in gel staining. UCSD approved EtBr alternatives include SybrSafe, EZ Vision, GelRed, and GelGreen. Any solid waste generated from the use of these dyes can be safely disposed of in the municipal trash.
The disposal of your liquid waste will depend on the type of buffer you use, the concentration of your buffer and the concentration of your dyes.
Of the most commonly used buffers, TE and TAE, TE can be sewered. TAE, however, will need to be collected as hazardous waste and picked up by EH&S. TAE falls within the California Toxic Range. Also, keep in mind any unused kits and concentrated reagents (pre-dilution) are still to be managed as hazardous waste as well.
If any of the EtBr alternatives are acceptable in your research, EH&S encourages you to phase out ethidium bromide. You’ll save important research time, reduce hazardous waste costs, and help make UC San Diego a safer and more sustainable campus.
|Fig 1: EtBr Stained Gel||Fig 2: SYBR Stained Gel|