BD OptiBuild™ BUV563 Rat Anti-Mouse CRIg

The 17C9 monoclonal antibody specifically recognizes Complement receptor of the immunoglobulin superfamily (CRIg) which is encoded by the Vsig4 (V-set and immunoglobulin domain containing 4) gene. CRIg is a ~45 kDa single-pass type I transmembrane glycoprotein that contains a variable (V-type) immunoglobulin domain in its extracellular region which is required for binding complement components and promoting phagocytosis. CRIg is expressed on Kupffer cells and tissue resident macrophages, including a subset of resident peritoneal macrophages. CRIg binds complement fragments C3b and iC3b and plays important roles in innate and adaptive immunity. This complement receptor is involved in regulation of the complement cascade and serves as a phagocytic receptor in the clearance of pathogens, immune complexes, and apoptotic cells. CRIg-positive macrophages can reportedly function in the negative regulation of T-cell proliferation and IL-2 production.

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.