The HB7 monoclonal antibody specifically binds to human CD38. CD38 is a type II transmembrane glycoprotein of 45 kDa with a protein core of 35 kDa. The CD38 antigen is expressed on essentially all pre-B lymphocytes, plasma cells, and thymocytes. It is also present on activated T lymphocytes, natural killer (NK) lymphocytes, myeloblasts, and erythroblasts. The antigen is expressed during the early stages of T- and B-lymphocyte differentiation, is lost during the intermediate stages of maturation, and then reappears during the final stages of maturation. The CD38 antigen is expressed on 90% of CD34+ cells, and is not expressed on pluripotent stem cells. Coexpression of CD38 antigen on CD34+ cells indicates lineage commitment of those cells. CD38 is a counter-receptor of CD31. It is also expressed in T- and B-acute lymphoblastic leukemia (ALL), Burkitt's lymphoma, multiple myeloma, acute myeloid leukemia (AML), and chronic lymphocytic leukemia (CLL).
The antibody was conjugated to BD Horizon™ BB700, which is part of the BD Horizon Brilliant™ Blue family of dyes. It is a polymer-based tandem dye developed exclusively by BD Biosciences. With an excitation max of 485 nm and an emission max of 693 nm, BD Horizon BB700 can be excited by the 488 nm laser and detected in a standard PerCP-Cy™5.5 set (eg, 695/40-nm filter). This dye provides a much brighter alternative to PerCP-Cy5.5 with less cross laser excitation off the 405 nm and 355 nm lasers.