The 30-F1 monoclonal antibody specifically recognizes CD24 which is also known as Heat-Stable Antigen (HSA or HsAg). CD24 is a highly glycosylated sialoprotein that is glycosylphosphatidylinositol (GPI)-linked to the cell membrane. CD24 is encoded by Cd24a (CD24a antigen) and is variably expressed on thymocytes, lymphocytes, monocytes, granulocytes, and erythrocytes. Hematopoietic stem cells of the embryonic yolk sac and fetal liver express CD24. The expressed levels of CD24 vary during the developmental stages of cells within the T and B cell lineages. In the bone marrow, hematopoietic progenitors acquire CD24 expression upon commitment to the lymphocyte lineage. Immature B cells in the bone marrow and spleen of adult mice express high levels of CD24, whereas mature peripheral B cells express intermediate levels of CD24. The majority of thymocytes express high levels of CD24, whereas mature thymic and peripheral T cells do not express CD24. In contrast, γδ TCR-bearing thymocytes which emigrate to the spleen are CD24+. Dendritic cells of the thymus, spleen, and liver and epidermal Langerhans cells reportedly express CD24 whereas NK cells and plasma cells do not. CD24 can function as an adhesion molecule and serve as a ligand for CD62P (P-selectin). It can be involved in the costimulation of CD4+ T cells by B cells as well as function as a "co-inducer" of in vitro thymocyte maturation. 30-F1 and other CD24-specific monoclonal antibodies, such as, M1/69 and J11d, can show subtle differences in the staining patterns for different lymphocyte populations. For this reason, the consistent use of the same CD24-specific antibody is recommended during research studies.
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.