CD40 (cluster of differentiation 40), a 48 kD type I glycoprotein, is a member of the TNFR superfamily, a costimulatory factor found on antigen presenting cells and is required for their activation. CD40 is primarily expressed on surface of dendritic cells, B cells, and macrophages and on endothelial, smooth muscle cells, and fibroblasts. Binding of CD40 to CD154 (CD40L) on T helper cells activates antigen presenting cells and enhances the expression of cytokines, chemokines, matrix metalloproteinases, growth factors, and adhesion molecules. CD40L on T cell also binds CD40 on B cell to induce its differentiation, isotype class-switching and protects B cells from apoptosis.

Each lot of antibody has been tested by flow cytometry staining. We suggest use ≤ 0.5 µg per million cells in 100 µl volume of staining buffer. Researchers are recommended to further titrate this antibody at the optimal concentration for each specific application.

Keep the lyophilized antibodies at -20 °C. Once reconstituted with PBS, store at 2 °C - 8 °C for less than 3 weeks or freeze at -20°C for long term storage. Please limit freeze and thaw cycles.