Diphtheria Toxin

The long term stability of this material in solution when stored at -20°C has not been determined. Stock solutions stored at -70°C are expected to be stable for one month.

This product is intended for laboratory or research use only, and no formal solution stability studies have been conducted. Before reconstitution, storage at 4°C in its original packaging is recommended, but specific duration guidelines are not provided. For reconstitution, use sterile distilled water to achieve a concentration of 1 mg of diphtheria toxin in 10 mM sodium phosphate with 5% lactose, pH 7.4. After reconstitution, unused toxin can be quick frozen in aliquots on dry ice and stored at -70°C. Thawing should be done quickly at room temperature. Repeated freezing and thawing or maintaining the preparation at 4°C for extended periods are not recommended, as these may lead to increased nicking. For assays using very low concentrations of the toxin, a carrier protein such as human serum albumin is suggested. The preparation migrates as a single major band under non-denaturing conditions, with a slower migrating band comprising less than 5% of the preparation, indicating an aggregate of diphtheria toxin. In the presence of a reducing agent, on SDS gels, the preparation shows a major band of approximately 63,000 daltons corresponding to the intact toxin, and two faster bands of approximately 39,000 and 24,000 daltons corresponding to the B and A fragments, respectively. The degree of nicking is estimated to be less than 5%. It is not recommended to store the solution frozen, and use within 1 month of resuspension is advised. The vial contains salts for TRIS and EDTA at pH 7.5.

Products that are robust in nature and extremely stable, in the original unopened container, are not assigned an expiration date or retest schedule. These products will have no dating reported on either the label or the Certificate of Analysis. This product falls under that category. The specification sheet is available at this link: https://www.sigmaaldrich.com/specification-sheets/872/957/D0564-BULK________SIGMA____.pdf

Products that are not assigned an expiration or retest date are covered by a warranty period of 1 year from the date of product shipment.

Full Product Dating Information may be reviewed at the link below: https://www.sigmaaldrich.com/deepweb/assets/sigmaaldrich/marketing/global/documents/190/408/product-dating-information-ms.pdf

No test has been conducted on this product for intraperitoneal injection. However, for intraperitoneal injection in mice, normal saline solution appears to be effective as a delivery solvent

Once the product is reconstituted in water, the solution may be stored in aliquots at -20°C. Avoid freeze-thawing. Long-term storage in the refrigerator at 2-8°C is not recommended.

For assays employing low concentration of the toxin, the use of a carrier protein like serum albumin is recommended.

This product is soluble in water.  Reconstitute with the volume of water described under Description on our website page for D0564.

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.

In the presence of a reducing agent, on SDS gels, this preparation migrates as a major band of approx. mw 63,000 Daltons (corresponding to thte intact toxin) and two faster more lightly stained bands of approx. MW 39,000 and 24,000 Daltons (corresponding to the B and A fragments, respectively). Based on this method, the extent of the degree of nicking in this preparation is estimated to be less than 5%.

Product D0564-1MG, Diphtheria Toxin, is packaged in a small serum vial with a rubber or silicone septum and aluminum crimp top. The product can be reconstituted in the vial by piercing the septum with a syringe fitted with a stainless steel needle.