Ethidium bromide

Ethidium bromide (EtBr) is a fluorescent dye commonly used in molecular biology laboratories for nucleic acid staining. It is an intercalating agent that inserts itself between the base pairs in the DNA double helix, allowing for the visualization of DNA and RNA in agarose gel electrophoresis and other techniques.

Properties

Ethidium bromide is a heterocyclic compound with the chemical formula C21H20BrN3. It is a dark red, crystalline, non-volatile solid that is soluble in water. When exposed to ultraviolet light, it fluoresces with an orange-red color, making it useful for detecting nucleic acids.

Applications

Ethidium bromide is primarily used in agarose gel electrophoresis to visualize DNA and RNA. When a gel containing nucleic acids stained with ethidium bromide is exposed to UV light, the nucleic acids fluoresce, allowing for their detection and analysis. This technique is widely used in genetic research, forensic science, and biotechnology.

Safety and Handling

Ethidium bromide is a potent mutagen and is considered hazardous. It can cause genetic mutations and is potentially carcinogenic. Proper safety measures, including the use of gloves, lab coats, and eye protection, should be taken when handling ethidium bromide. Disposal of ethidium bromide waste should follow appropriate hazardous waste disposal protocols.

Alternatives

Due to its toxicity, several safer alternatives to ethidium bromide have been developed. These include SYBR Green, GelRed, and GelGreen, which are less hazardous and provide similar or better sensitivity for nucleic acid detection.

See also

• Agarose gel electrophoresis
• DNA
• RNA
• Fluorescent dye
• Mutagen
• Carcinogen