The 24D2 monoclonal antibody specifically recognizes CD340 which is also known as Human epidermal growth factor receptor 2 (HER-2 or HER2), Neu (neuro/glioblastoma derived oncogene homolog), or Metastatic lymph node gene 19 protein (MLN19). CD340 (HER-2) is a ~185 kDa type I transmembrane glycoprotein that is encoded by ERBB2 (erb-b2 receptor tyrosine kinase 2) and belongs to the ERBB family of receptor tyrosine kinases that includes EGFR, HER3, and HER4. Although CD340 (HER-2) has no identified direct-binding ligand, it can form heterodimers with other ligand-bound ERBB family members. CD340 (HER-2) helps activate intracellular signaling pathways including mitogen-activated protein kinase (MAPK) and phosphatidylinositol-3 kinase (PI-3K) through its cytoplasmic tyrosine kinase-containing region. CD340 (HER-2) is expressed by bone marrow mesenchymal stem cells. It is overexpressed and plays a significant role in the development of multiple human cancers including some leukemias, neuroblastomas, and carcinomas of the breast, ovary, cervix, colon, and lung.
The antibody was conjugated to BD Horizon™ BUV496 which is part of the BD Horizon Brilliant™ Ultraviolet family of dyes. This dye is a tandem fluorochrome of BD Horizon BUV395 with an Ex Max of 348-nm and an acceptor dye with an Em Max at 496-nm. BD Horizon BUV496 can be excited by the ultraviolet laser (355 nm) and detected with a 515/30 nm filter with a 450LP. Due to the excitation of the acceptor dye by other laser lines, there may be significant spillover into the channel detecting BD Horizon V500 or BV510 (eg, 525/40-nm filter). However, the spillover can be corrected through compensation as with any other dye combination.