Ethidium bromide has been used for decades to detect nucleic acids in agarose gels because it is inexpensive, sensitive enough for routine applications, and simple to use. However, because ethidium bromide has been shown to be mutagenic in the Ames test, it is potentially hazardous to laboratory workers and the environment, and institutions commonly require it to be disposed of as hazardous waste. Because of this, many users seek to find safer alternatives to ethidium bromide for gel electrophoresis. Biotium developed red fluorescent GelRed™ and green fluorescent GelGreen™ as safer replacements for ethidium bromide. GelRed™ and GelGreen™ are non-toxic and non-mutagenic because they do not bind DNA in living cells due to their membrane impermeability.

A number of other alternative gel stains have been marketed as safer alternatives to ethidium bromide. Biotium performed a comparison of several alternative gel stains to evaluate their live cell permeability and sensitivity in gel staining. They found that many of these gel stains are membrane permeable dyes that readily penetrate living cells and stain the nucleus and other cellular structures. Chemical analysis showed that several of these products contain dyes that are known to be cytotoxic and to potentiate DNA damage by mutagens. In contrast, GelRed™ and GelGreen™ do not readily penetrate the nuclei of living cells. Furthermore, GelRed™ and GelGreen™ provide superior sensitivity in gel staining compared to other so-called safe nucleic acid gel stain

Benefits of GelRed® and GelGreen®:

• Ultra-sensitive and stable

• Stable at room temperature

• Compatible with standard UV transilluminators

• Use in precast gels or as a post-stain

• Non-toxic or mutagenic (non-hazardous waste)

• Compatible with downstream applications such as cloning and sequencing