Chelex 100

Chelex 100 is a chelating material from Bio-Rad^[1] 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.

Chelex resin is often used for DNA extraction in preparation for PCR. The exact role of Chelex in DNA preparation is uncertain. The Chelex appears to protect the DNA from the effects of the heating used to release the DNA from the cells, perhaps through sequestering divalent heavy metals that would otherise damage the DNA.^[2] Polar resin beads bind polar cellular components after breaking open cells, while DNA and RNA remain in water solution above chelex.

References

1. ^ "Chelex® 100 and Chelex 20 Chelating Ion Exchange Resin Instruction Manual" (PDF). http://www.bio-rad.com/webmaster/pdfs/9184_Chelex.PDF. 
2. ^ Walsh, P.S., Metzger D.A., and Higuchi, R. (1991). "Chelex 100 as a Medium for Simple Extraction of DNA for PCR-Based Typing from Forensic Material". BioTechniques 10 (4): 506–513. PMID 1867860. 

• Daniel Harris. Quantitative Chemical Analysis, seventh edition, 2007. ISBN 0-7167-7041-5. Page 594.
• R. N. Ceo, M. R. Kazerouni, and K. Rengan (1993). "Sorption of silver ions by Chelex 100 chelating resin". Journal of Radioanalytical and Nuclear Chemistry, Articles 172 (1): 43–48. doi:10.1007/BF02040660. 

External links

• Official site