The P84 monoclonal antibody specifically binds to CD172a, also known as SIgnal-Regulatory Protein α (SIRPα), Src Homology 2 domain-containing protein tyrosine Phosphatase (SHP) Substrate 1 (SHPS-1), or Brain Immunoglobulin-like molecule with Tyrosine-based activation motifs (BIT). CD172a is an adhesion molecule of the Ig superfamily which is expressed on neurons in the central nervous system and the retina, on macrophages, and on bone-marrow myeloid cells. Its ligand, CD47, or Integrin-Associated Protein (IAP), is expressed by a wide variety of cells. CD172a and CD47 are proposed to mediate bi-directional signaling to modify neural synaptic activity and regulate the phagocytic activities of macrophages.
The antibody was conjugated to BD Horizon™ BUV563 which is part of the BD Horizon Brilliant™ Ultraviolet family of dyes. This dye is a tandem fluorochrome of BD Horizon BUV395 which has an Ex Max of 348 nm and an acceptor dye. The tandem has an Em Max at 563 nm. BD Horizon BUV563 can be excited by the 355 nm ultraviolet laser. On instruments with a 561 nm Yellow-Green laser, the recommended bandpass filter is 585/15 nm with a 535 nm long pass to minimize laser light leakage. When BD Horizon BUV563 is used with an instrument that does not have a 561 nm laser, a 560/40 nm filter with a 535 nm long pass may be more optimal. Due to the excitation and emission characteristics of the acceptor dye, there may be spillover into the PE and PE-CF594 detectors. However, the spillover can be corrected through compensation as with any other dye combination.