Chelex 100

Chelex 100 is a chelating resin used to purify other compounds via ion exchange. It is noteworthy for its ability to bind transition metal ions.

It is a styrene-divinylbenzene resin containing iminodiacetic acid groups.

A concentrated solution of metals is obtained by eluting the resin with a small volume of 2 M nitric acid, which protonates the iminodiacetate groups.

Chelex resin is often used by DNA extraction. Polar resin beads binds polar cellular components after breaking open cells. Non-polar nuclear DNA and RNA remain in water solution above chelex.