The B4B6 monoclonal antibody specifically binds to CD172b, which is also known as Signal regulatory protein β (SIRPβ), or SIRP-beta-1 (SIRPB1/SIRPβ1). CD172b is a 50 kDa, type I transmembrane glycoprotein that belongs to the SIRP family within the Ig gene superfamily. CD172b has a transmembrane domain that contains a positively-charged lysine residue. This allows CD172b to interact with a transmembrane signaling adaptor protein, DAP12/KARAP, and transduce stimulatory signals into cells. CD172b is expressed on monocytes, macrophages, dendritic cells, and granulocytes. It is not expressed on CD34+ cells. CD172b/SIRPβ and its counterpart, CD172a/SIRPα, appear to have complementary roles in signal regulation and may work together in tuning cellular responses to certain ligands. This clone has been reported not to cross-react with CD172a.
The antibody was conjugated to BD Horizon™ BV510 which is part of the BD Horizon Brilliant™ Violet family of dyes. With an Ex Max of 405-nm and Em Max at 510-nm, BD Horizon BV510 can be excited by the violet laser and detected in the BD Horizon V500 (525/50-nm) filter set. BD Horizon BV510 conjugates are useful for the detection of dim markers off the violet laser.