The APA5 antibody monoclonal antibody specifically binds to CD140a, the Platelet-Derived Growth Factor Receptor alpha chain (PDGFR-a, PDGFR-α). CD140a is a receptor tyrosine kinase that is widely expressed on cells of mesenchymal origin in the embryo and adult. CD140a is expressed on several other cell types during embryonic development, but not on hematopoietic cells. CD140a binds to PDGF A and B chains, in contrast to PDGFR-b (CD140b) that binds only to the PDGF B chain. Biologically active PDGF is a disulphide-linked dimer, forming the AA, AB, and BB isoforms. Ligand binding to the PDGF Receptor induces the formation of receptor dimers (aa, ab, or bb), autophosphorylation, and internalization. The APA5 antibody has been demonstrated to block binding of PDGF-AA to PDGFR-a-expressing cells in vitro and to block some PDGF-mediated developmental events in vivo.
The antibody was conjugated to BD Horizon™ BV711 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 711-nm. BD Horizon BV711 can be excited by the violet laser and detected in a filter used to detect Cy™5.5 / Alexa Fluor® 700-like dyes (eg, 712/20-nm filter). Due to the excitation and emission characteristics of the acceptor dye, there may be moderate spillover into the Alexa Fluor® 700 and PerCP-Cy5.5 detectors. However, the spillover can be corrected through compensation as with any other dye combination.