The BB9 monoclonal antibody specifically binds Angiotensin-converting enzyme (ACE) which is also known as Dipeptidyl carboxypeptidase 1 (DCP1) or CD143. CD143 is a type I transmembrane glycoprotein that functions as a zinc metallopeptidase involved with the metabolism of angiotensin, bradykinin, and other oligopeptides. It is expressed on primitive hematopoietic progenitor cells (HPC). BB9 reacts with stromal cells, a minor subset of human bone marrow cells; it does not react with peripheral blood leucocytes. BB9 recognizes a subset of CD34+CD90+ cells that demonstrate low or absent expression of CD38, low retention of Rhodamine 123 and are Ki-67-negative. CD34+BB9+ cells are able to sustain hematopoiesis in pre-CFU culture stimulated with IL-3, IL-6, G-CSF, and SCF. BB9 also reacts with a subset of CD34+ cells from mobilized peripheral blood. This antibody was generated using human bone marrow-derived stromal cells as immunogen.
The antibody was conjugated to BD Horizon™ BV421 which is part of the BD Horizon Brilliant™ Violet family of dyes. With an Ex Max of 407-nm and Em Max at 421-nm, BD Horizon BV421 can be excited by the violet laser and detected in the standard Pacific Blue™ filter set (eg, 450/50-nm filter). BD Horizon BV421 conjugates are very bright, often exhibiting a 10 fold improvement in brightness compared to Pacific Blue conjugates.