The HIP1 monoclonal antibody specifically binds to CD42b. CD42b is also known as the Platelet glycoprotein Ib alpha chain that is encoded by the GP1BA gene. CD42b is disulfide bonded to CD42c to form a 170 kDa heterodimer, GPIb. GPIb forms a noncovalent complex with CD42a and CD42d (CD42 complex) that is expressed on platelets and megakaryocytes. The CD42 complex serves as the von Willebrand Factor (vWF) surface receptor involved in the adhesion of platelets to the subendothelium of damaged vascular walls. HIP1 inhibits the ristocetin-dependent binding of vWF to platelets and partially inhibits collagen-induced aggregation.
The antibody was conjugated to BD Horizon™ BV650 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 650-nm. BD Horizon BV650 can be excited by the violet laser and detected in a filter used to detect APC-like dyes (eg, 660/20-nm filter). Due to the excitation and emission characteristics of the acceptor dye, there will be spillover into the APC and Alexa Fluor® 700 detectors. However, the spillover can be corrected through compensation as with any other dye combination.