mAb 24 (also known as 24 or m24) specifically recognizes a divalent cation-dependent epitope expressed by active human Integrin β2 which is also known as CD18. Integrin β2 is an ~95 kDa type I transmembrane glycoprotein that is encoded by ITGB2 (integrin subunit beta 2). Integrin β2 (CD18) noncovalently associates with other integrin α chains to form αLβ2 (CD11a/CD18; also known as, LFA-1), αMβ2 (CD11b/CD18; Mac-1, CR3), αXβ2 (CD11c/CD18; p150,95; CR4) and αDβ2 (CD11d/CD18) heterodimers. These integrins are variably expressed on lymphocytes, NK cells, neutrophils, eosinophils, basophils, monocytes, macrophages, Langerhans cells, and dendritic cells (DCs). These leucocyte integrins bind to various ligands and mediate cellular adhesion and signaling responses that regulate cellular activation, effector function, and migration. mAb 24 binds to the extended/open, high-affinity ligand-binding conformation of active Integrin β2 (CD18). mAb 24 can be used as a reporter antibody for the activated status of Integrin β2-containing receptors expressed by leucocytes in response to various stimuli in the presence of Mg2+ or Mn2+.
The antibody was conjugated to BD Horizon BV750 which is part of the BD Horizon Brilliant™ Violet family of dyes. This dye is a tandem fluorochrome of BD Horizon BV421 with an Ex Max of 405-nm and an acceptor dye with an Em Max at 750-nm. BD Horizon Brilliant BV750 can be excited by the violet laser (405 nm) and detected with a 750/30 nm filter with a 740 nm long pass. Due to spectral differences between labeled cells and beads, using BD™ CompBeads can result in incorrect spillover values when used with BD Horizon BV750 reagents. Therefore, the use of BD CompBeads or BD CompBeads Plus to determine spillover values for these reagents is not recommended.