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C7901

Sigma-Aldrich

Chelex® 100 sodium form

50-100 mesh (dry)

Synonym(s):

Iminodiacetic Acid Resin

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About This Item

CAS Number:
MDL number:
UNSPSC Code:
23151817
NACRES:
NA.56
Pricing and availability is not currently available.

form

beads

Quality Level

matrix

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

4-14

capacity

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

Application

Chelex is used in affinity chromatography, protein chromatography, chelating resins, affinity resins and core bioreagents.
Chelex® 100 sodium form has been used:
  • for the extraction of DNA from bee samples [1]
  • to remove from cigarette smoke extract (CSE) and study the effects of hepcidin expression in the murine lungs[2]
  • to extract DNA from bacterial cultures[3]

Biochem/physiol Actions

Chelex® 100 is a styrene-divinylbenzene copolymer containing paired iminodiacetate ions, which act as chelating groups in binding polyvalent metal ions.[4] It is considered a weakly acidic resin. Chelex acts as a chelating resin that is used in DNA extraction from forensic samples, such as hair, bloodstain cards, and buccal swabs.[4]

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

WGK 3

Flash Point(F)

Not applicable

Flash Point(C)

Not applicable

Personal Protective Equipment

dust mask type N95 (US), Eyeshields, Gloves

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Customers Also Viewed

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
Methods for extracting genomic DNA from whole blood samples: current perspectives
Chacon Cortes D, et al.
Journal of Biosciences, 2014(2), 1-9 (2014)
Elizabeth Perez et al.
Journal of immunology (Baltimore, Md. : 1950), 205(9), 2489-2498 (2020-09-23)
Chronic obstructive pulmonary disease (COPD) is a debilitating lung disease associated with cigarette smoking. Alterations in local lung and systemic iron regulation are associated with disease progression and pathogenesis. Hepcidin, an iron regulatory peptide hormone, is altered in subjects with
Simultaneous detection of Escherichia coli O175: H7, Salmonella spp., and Listeria monocytogenes by multiplex PCR
Germini A, et al.
Food Control, 20(8), 733-738 (2009)
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

Questions

1–9 of 9 Questions  
  1. Can this resin be used with organic solvents (such as DMF, DMSO) in order to remove Cu ? For example in solid-phase peptide synthesis?

    1 answer
    1. The base matrix of the resin is styrene divinylbenzene which is chemically compatible with organic solvents at low concentrations.

      Chelex 100 resin is not damaged by 100% organics, but it IS affected.

      1) The functional group will lose its polarity and metals won't exchange onto the resin:

      2) Chelex 100 resin will not work as an ion exchanger in 100% organic solvent.

      3) In studies, Chelex 100 resin removed metal ions well in either 20 or 40% ethanol. End users should verify the efficiency of metal ion removal with the sample being treating. Perhaps doing a specific assay for the metal ions would help quantitate the metal content of the buffers before and after treatment. A batch overnight treatment of the solutions would remove metal ions more efficiently than a one hour treatment, particularly in the ethanol solutions.

      Note, ethanol will shrink the resin beads and decrease the porosity of the resin, and this would decrease the efficiency of the exchange, particularly for larger metallic ions. Thus a solution of 40% ethanol will require a longer incubation time to remove all of the metal ions. Increasing the Chelex treatment time would allow more time for ion exchange to occur.

      Stryrene divinylbenzene and iminodiacetic acid (the functional group) can leach from the resin, and this would be increased with the higher concentration of ethanol. The recommendation is to wash the resin with 100% ethanol and then equilibrate in aqueous solution immediately before using the resin. If the failure to aggregate is due to something leaching from the resin, this experiment should eliminate this possibility.

      Also, the carboxyl groups on the resin have a very high selectivity for hydrogen ions, and will exchange hydrogen ions from water, resulting in an increased pH. There is no solution for this except to try equilibrating the resin using the protocol in the instruction manual (this doesn't work very well) or to adjust the pH of the buffer after the Chelex treatment.. The functional group will lose its polarity and metals won't exchange onto the resin. Studies have indicated the resin is still functional in 20% methanol and ethanol.

      Organic solvents such as DMSO or DMF might also affect the selectivity of the resin slightly for divalent cations and would reduce the interaction between small hydrophobic molecules and the resin matrix. The resin may also swell upon exposure to the chemicals, but it won't melt or dissolve.

      Helpful?

  2. Can this be used to remove calcium from FBS for Keratinocyte culture ?

    1 answer
    1. This product has been used to remove calcium from FBS. However, the application has not been validated internally.

      Helpful?

  3. How is the Chelex 100 resin used and how is it washed back? Can you please provide a manual of its usage?

    1 answer
    1. Please see the link below to review the washing steps and usage instructions provided in the product datasheet.
      https://www.sigmaaldrich.com/deepweb/assets/sigmaaldrich/product/documents/200/928/c7901pis.pdf

      Helpful?

  4. What is the grade (analytical; technical; molecular biology, or... ) of this reagent?

    1 answer
    1. This product is not assigned a specific grade or tested for a specific application.

      Helpful?

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

    1 answer
    1. 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.

      Helpful?

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

    1 answer
    1. 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.

      Helpful?

  7. 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?

    1 answer
    1. 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.

      Helpful?

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

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

      Helpful?

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

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

      Helpful?

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