Rapamycin, 25 mg

STEMCELL Technologies supplies this small molecule as a crystalline solid. It is described as a macrolide antibiotic and immunosuppressive compound that inhibits mammalian target of rapamycin (mTOR) signaling. The compound forms a complex with cytosolic FK-binding protein 12 (FKBP-12), which directly binds to mTOR complex 1 (mTORC1). Its immunosuppressive effects are mediated through inhibition of IL-2 signaling that is critical for T cell proliferation and activation, and it shows antifungal activity against Candida albicans and other fungi.

Properties include a molecular weight of 914.2 g/mol, chemical formula C51H79NO13, and a reported purity of ≥ 95%. Alternative names listed are AY 22989, Cypher, NSC 226080, and Sirolimus, with CAS number 53123-88-9. The product is stable at -20°C as supplied, should be protected from prolonged exposure to light, and remains stable as supplied for 12 months from the date of receipt.

The compound has low solubility in aqueous media and is soluble in DMSO up to 10 mM and in absolute ethanol up to 0.25 mM. For use as a cell culture supplement, the stock solution should be diluted into culture medium immediately before use, with the final DMSO concentration kept below 0.1% to avoid potential cell toxicity. Published applications include the induction of autophagy in malignant glioma cells.