The M-A251 monoclonal antibody specifically binds to the 55 kDa type I transmembrane glycoprotein known as low-affinity interleukin-2 receptor alpha chain subunit (IL-2Rα). CD25 is expressed on regulatory T cells, activated lymphocytes (T and B), and monocytes. It associates with the IL-2Rβ/CD122 and IL-2Rγ/CD132 receptor chains to form the high-affinity IL-2R complex. CD25 expression on T and B lymphocytes is upregulated by antigenic or mitogenic stimulation. Soluble CD25/IL-2Rα is produced as a consequence of lymphocyte stimulation and is found in biological fluids following inflammatory responses.
The antibody was conjugated to BD Horizon™ BUV395 which is part of the BD Horizon Brilliant™ Ultraviolet family of dyes. This dye has been exclusively developed by BD Biosciences to have minimal spillover into other detectors, making it an optimal choice for multicolor flow cytometry. With an Ex Max at 348 nm and an Em Max at 395 nm, BD Horizon BUV395 can be excited with a 355 nm laser and detected with a 379/28 filter.