The 1.78.1 monoclonal antibody specifically binds to the human Thrombopoietin Receptor (TPO-R) that is also know as the Myeloproliferative leukemia protein (c-Mpl) or CD110. CD110 is a type I transmembrane protein and a member of the hematopoietin receptor family. It is expressed on hematopoietic stem cells, a subfraction of hematopoietic precursor cells, cells of the megakaryocytic lineage and platelets. CD110 serves as a receptor for thrombopoietin. Upon binding of thrombopoietin to CD110, megakaryocyte proliferation and differentiation is induced and stem cells are protected from apoptosis.
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.