Protocols which require the use of electrophoresis gels require several specific waste management procedures to be in place. The following are general guidelines for electrophoresis-related waste:
- Ethidium Bromide is a commonly-used chemical in the electrophoresis process. Ethidium Bromide (“EtBr”) is a suspected mutagen; for this reason, the University of Florida requires lab workers to handle both concentrated stock solutions containing Ethidium Bromide, as well as agarose gels stained with Ethidium Bromide as Hazardous Waste.
- All other materials involved with the processing or use of Ethidium Bromide (including diluted solutions, running buffers, de-stained Agarose gels, rinsates, and solid materials which have contacted only Ethidium Bromide solutions) may be safely disposed of down sink drains (if liquid waste) or as Clean Lab Ware (if solid waste) as long as no other hazardous materials are also present in the waste. The concentration of Ethidium Bromide in these materials has been judged low enough that no significant hazard is present.
Note: Ethidium Bromide gels can be easily de-stained in the laboratory by simply placing the gels in a DI-water bath for 15 minutes and gently agitating the gels. This eliminates the need to collect the gels as a hazardous waste, and labs are, therefore, highly encouraged to do so.
- There are many other products currently on the market which mimic the performance of Ethidium Bromide, but which are not considered hazardous waste once they are spent. Dilute solutions of these products, along with the associated stained gels, may be drain disposed (if liquid waste) or disposed of as Clean Lab Ware (if solid waste). The following products have been researched and determined to be less-hazardous than Ethidium Bromide, and wastes may be managed using these less-stringent methods.
- SYBR Green
- SYBR Gold
Unused portions of these products, however, because of their higher concentrations, must be disposed of through EH&S as hazardous waste.
- Several other dyes common in the electrophoresis process include xylene cyanol, methylene blue, bromophenol blue, and cresol red. Unused portions of these dyes should be turned over to EH&S for disposal as hazardous waste, while dilute aqueous solutions containing the dyes may be disposed of down sink drains as long as no other hazardous materials are also present in the waste. These dyes are commonly combined with flammable solvents such as xylene, methanol, or alcohols; if waste solutions contain any concentration of these solvents, labs should manage the waste as hazardous waste.
- Environmental Health and Safety’s Chemical and Radioactive Waste Disposal group can provide containers for electrophoresis waste collection at no charge to UF labs. 5-gallon plastic buckets are commonly used to contain agarose gel waste, while bottles or carboys will be provided for collection of liquid wastes. To request a container delivery, call 392-8400.