The ALMA.16 monoclonal antibody specifically recognizes CD42a. CD42a is a 17-22 kDa type I transmembrane glycoprotein that is also known as Platelet glycoprotein IX (GPIX), or Glycoprotein 9 (GP9). CD42a forms a noncovalently linked complex (GPIb/GPIX/GPV) with CD42b, CD42c and CD42d that may serve as a receptor for von Willebrand factor. It is expressed on platelets and megakaryocytes and is absent on the platelets of patients with Bernadr-Soulier Syndrome (BSS). Although the CD42a function is not fully understood, GPIX glycoprotein is important for the assembly and membrane expression of the CD42 complex and for the maintenance of the functional conformation of CD42b (GPIb).
The antibody was conjugated to BD Horizon™ BUV496 which is part of the BD Horizon Brilliant™ Ultraviolet family of dyes. This dye is a tandem fluorochrome of BD Horizon BUV395 with an Ex Max of 348-nm and an acceptor dye with an Em Max at 496-nm. BD Horizon BUV496 can be excited by the ultraviolet laser (355 nm) and detected with a 515/30 nm filter with a 450LP. Due to the excitation of the acceptor dye by other laser lines, there may be significant spillover into the channel detecting BD Horizon V500 or BV510 (eg, 525/40-nm filter). However, the spillover can be corrected through compensation as with any other dye combination.