EDTA (ethylenediaminetetraacetic acid) is a polyamino carboxylic acid. It is a colorless, water-soluble solid and is useful as a chelating agent due to its ability to "sequester" metal ions such as Ca2+ and Fe3+. These cations are responsible for various undesirable effects in molecular biological and cell culture processes. After being bound by EDTA, these metal ions remain in the solution but exhibit diminished reactivity. The use of EDTA therefore allows for greater control over many experiments.