Hu Recom CD40 Ligand, 500 µg

Manufactured by STEMCELL Technologies, this human recombinant protein is a type II transmembrane glycoprotein belonging to the tumor necrosis factor (TNF) superfamily. CD40 ligand forms a bioactive homotrimer that exists as both soluble and membrane-bound forms and is expressed on T cells, monocytes, basophils, eosinophils, platelets, dendritic cells, and endothelial cells. Its receptor, CD40, is expressed on B cells, dendritic cells, macrophages, monocytes, platelets, endothelial cells, and epithelial cells. Binding of CD40 ligand to CD40 stimulates B cell proliferation, immunoglobulin class switching, antibody secretion, and T cell-dependent humoral responses. Dysregulation of CD40 ligand has been linked to immune deficiency in HIV and AIDS, as well as to the pathology of atherosclerosis, atherothrombosis, and restenosis.

The product is supplied lyophilized from a sterile-filtered solution containing sodium phosphate at pH 7.5 and has a predicted molecular mass of 16.3 kDa. Reported purity is ≥ 95%. Specific activity is ≥ 1 x 10^4 units/mg, determined by the ability to induce bioluminescence in engineered CD40L bioassay cells, with an EC50 of ≤ 100 ng/mL. Endotoxin level is ≤ 0.1 EU/μg protein, as measured by kinetic Limulus amebocyte lysate (LAL) analysis. The protein is expressed in E. coli and is intended for research use only. According to the safety data sheet, the product is not classified as a hazardous substance or mixture according to the Globally Harmonized System (GHS).

For storage, the lyophilized product should be kept at -20 to -80°C and is stable as supplied for 12 months from the date of receipt. The vial should be centrifuged before opening, and the product reconstituted in sterile water to at least 0.1 mg/mL by pipetting the solution down the sides of the vial; vortexing should be avoided. After reconstitution, if not used immediately, the product may be diluted with concentrated bovine serum albumin (BSA) to a final BSA concentration of 0.1%. As a general guide, stock solutions should not be stored at 2 - 8°C for more than 1 month or at -80°C for more than 3 months, and repeated freeze-thaw cycles should be avoided.