Ethidium bromide is an intercalating agent commonly used as a fluorescent tag in molecular biology laboratories for techniques such as agarose gel electrophoresis. It is commonly abbreviated as EtBr, which is also an abbreviation for bromoethane.

What is ethidium bromide and why is it used?

Ethidium Bromide (EtBr) is sometimes added to running buffer during the separation of DNA fragments by agarose gel electrophoresis. It is used because upon binding of the molecule to the DNA and illumination with a UV light source, the DNA banding pattern can be visualized.

Is ethidium bromide a dye?

Ethidium bromide is the most commonly used dye for DNA and RNA detection in gels. Ethidium bromide is a DNA intercalator, inserting itself between the base pairs in the double helix. Ethidium bromide has UV absorbance maxima at 300 and 360 nm, and an emission maximum at 590 nm.