Chelex 100 (original) (raw)

Chelex 100 is a chelating material from Bio-Rad used to purify other compounds via ion exchange. It is noteworthy for its ability to bind transition metal ions. It is a styrene-divinylbenzene co-polymer 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. However, the heating steps do denature the double helix, and the resulting single-stranded DNA is less stable in storage.