Chelex 100
Encyclopedia
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.
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. Polar resin beads bind polar cellular components after breaking open cells, while DNA and RNA remain in water solution above chelex.
Bio-Rad
Bio-Rad Laboratories, Inc. , was founded in 1952 in Berkeley, California. The company was initially engaged in the development and production of specialty chemicals used in biochemical, pharmaceutical, and other life science research applications...
used to purify other compounds via ion exchange
Ion exchange
Ion exchange is an exchange of ions between two electrolytes or between an electrolyte solution and a complex. In most cases the term is used to denote the processes of purification, separation, and decontamination of aqueous and other ion-containing solutions with solid polymeric or mineralic 'ion...
. It is noteworthy for its ability to bind transition metal
Transition metal
The term transition metal has two possible meanings:*The IUPAC definition states that a transition metal is "an element whose atom has an incomplete d sub-shell, or which can give rise to cations with an incomplete d sub-shell." Group 12 elements are not transition metals in this definition.*Some...
ions.
It is a styrene-divinylbenzene co-polymer containing iminodiacetic acid
Iminodiacetic acid
Iminodiacetic acid, HN2, often abbreviated to IDA, is an dicarboxylic acid amine. The iminodiacetate anion can act as a tridentate ligand to form a metal complex with two, fused, five membered chelate rings...
groups.
A concentrated solution of metals is obtained by eluting the resin with a small volume of 2 M nitric acid
Nitric acid
Nitric acid , also known as aqua fortis and spirit of nitre, is a highly corrosive and toxic strong acid.Colorless when pure, older samples tend to acquire a yellow cast due to the accumulation of oxides of nitrogen. If the solution contains more than 86% nitric acid, it is referred to as fuming...
, 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. Polar resin beads bind polar cellular components after breaking open cells, while DNA and RNA remain in water solution above chelex.