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Chelex® 100 sodium form

50-100 mesh (dry)

CAS Number:
MDL number:

Quality Level


1% cross-linked polystyrene
cross-linked polystyrene beads

matrix active group

iminodiacetic acid (sodium form)
paired iminodiacetate groups

matrix attachment

through methyl group to aromatic rings

particle size

50-100 mesh (dry)

pH range

4 - 14


≥0.3 meq/mL binding capacity
0.6 meq/g binding capacity (heavy metal ions)

General description

Chelex® 100 is a styrene-divinylbenzene copolymer containing paired iminodiacetate ions, which act as chelating groups in binding polyvalent metal ions. It is considered a weakly acidic resin.


Chelex is used in affinity chromatography, protein chromatography, chelating resins, affinity resins and core bioreagents.


25, 50, 100, 500 g in poly bottle

Other Notes

Product is autoclavable in sodium form. It has a maximum operating temperature of 75°C and is not soluble in water.

Legal Information

Chelex is a registered trademark of Bio-Rad Laboratories, Inc.

Storage Class Code

11 - Combustible Solids

WGK Germany


Flash Point(F)

Not applicable

Flash Point(C)

Not applicable

Personal Protective Equipment

dust mask type N95 (US),Eyeshields,Gloves

Certificate of Analysis

Certificate of Origin

  1. Which document(s) contains shelf-life or expiration date information for a given product?

    If available for a given product, the recommended re-test date or the expiration date can be found on the Certificate of Analysis.

  2. How do I get lot-specific information or a Certificate of Analysis?

    The lot specific COA document can be found by entering the lot number above under the "Documents" section.

  3. What solvent should I use to swell the Product C7901, Chelex 100 at the beginning?

    We recommend using a good grade of water (deionized or distilled).

  4. My Chelex 100 (Product C7901) in my column dried out.  Can I still use it?

    The resin may be rehydrated and used, as long as it remains white.  If the color of the re-swollen resin is yellow, do not use it.

  5. I want to use Product C7901, Chelex 100, to make a metal-free solution.  However, the water wash from the Chelex resin is very basic.  How can I fix this?

    A suspension of Chelex 100 (sodium form) in water typically has a pH of 10-11. This pH can be slowly lowered by extended water washing, or by using a buffer.  The sodium form at pH 6.3 can be obtained by rinsing with at least 4 bed volumes of 0.5 N sodium acetate buffer, followed by 5 bed volumes of water. This is a more common method for making metal-free distilled water.

  6. What is the particle size of the resin in Product C7901, Chelex 100?

    The particle size for this resin is 45-165 microns. The mean particle size is 90 microns.

  7. How do I find price and availability?

    There are several ways to find pricing and availability for our products. Once you log onto our website, you will find the price and availability displayed on the product detail page. You can contact any of our Customer Sales and Service offices to receive a quote.  USA customers:  1-800-325-3010 or view local office numbers.

  8. What is the Department of Transportation shipping information for this product?

    Transportation information can be found in Section 14 of the product's (M)SDS.To access the shipping information for this material, use the link on the product detail page for the product. 

  9. My question is not addressed here, how can I contact Technical Service for assistance?

    Ask a Scientist here.

T P Ryan et al.
Journal of biochemical toxicology, 8(1), 33-39 (1993-03-01)
The effects of transition metals on nonenzymatic and ceruloplasmin catalyzed epinephrine oxidation were investigated by studying rates of epinephrine oxidation in purified buffers and in the presence of metal chelating agents. We found that epinephrine does not "autoxidize" in sodium...
João Pedro Amorim et al.
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Rizwan Mahmud et al.
Journal of molecular microbiology and biotechnology, 29(1-6), 43-56 (2019-12-19)
The human gut is inhabited by several hundred different bacterial species. These bacteria are closely associated with our health and well-being. The composition of these diverse commensals is influenced by our dietary intakes. Non-caloric artificial sweeteners (NAS) have gained global...
Vit Molva et al.
Insect science, 27(2), 266-275 (2018-08-14)
The interaction of house dust mites (HDM) and microorganisms is the key factor in the survival of these mites in human-made environments. Spent growth medium (SPGM) provides the rest of the diet, along with dead mite bodies and microorganisms. SPGM...
Pepijn W Kooij et al.
Insects, 9(4) (2018-12-14)
Leaf-cutting ants are often considered agricultural pests, but they can also benefit local people and serve important roles in ecosystems. Throughout their distribution, winged reproductive queens of leaf-cutting ants in the genus Atta Fabricius, 1804 are consumed as a protein-rich...

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