The OX-41 monoclonal antibody specifically reacts with the rat signal-regulatory protein (SIRP). The rat SIRP (CD172) is a 110-120-kDa type 1 transmembrane protein with three extracellular immunoglobulin superfamily domains and two intracellular Immunoreceptor Tyrosinebased Inhibitory Motifs (ITIM). The SIRP ITIMs are phosphorylated in response to activation by growth hormone, epidermal growth factor, and integrin-mediated cell adhesion. The phosphorylated SIRP associates with tyrosine phosphatases SHP-1 and/or SHP-2. In the rat, SIRP is selectively expressed on myeloid cells (monocytes, macrophages, granulocytes, and dendritic cells) and neurons. The ligand for rat SIRP is CD47, which is similar to the interaction of the human homolog SIRPα1 (CD172α) and human CD47. The SIRP/CD47 interaction is thought to be important in maintaining cellular adhesion and possibly promote T-cell activation.
This antibody is conjugated to BD Horizon™ BV605 which is part of the BD Horizon Brilliant™ Violet family of dyes. With an Ex Max of 407-nm and Em Max of 602-nm, BD Horizon BV605 can be excited by a violet laser and detected with a standard 610/20-nm filter set. BD Horizon BV605 is a tandem fluorochrome of BD Horizon BV421 and an acceptor dye with an Em max at 605-nm. Due to the excitation of the acceptor dye by the green (532 nm) and yellow-green (561 nm) lasers, there will be significant spillover into the PE and BD Horizon PE-CF594 detectors off the green or yellow-green lasers. BD Horizon BV605 conjugates are very bright, often exhibiting brightness equivalent to PE conjugates and can be used as a third color off of the violet laser.