CD34, human

The antibody clone QBEND/10 reacts with an epitope on endothelial cells and haematopoietic progenitor cells, which is not sensitive to neuraminidase but to chymopapain and glycoprotease (CD34 class II antibodies). It may be used for the detection of endothelial cells and haematopoietic progenitor cells in tissues, cell smears and cell cultures. The CD34 molecule is a glycoprotein (110 kDa), which is expressed as well by endothelial cells as by haematopoietic precursor cells (BFU-E, CFU-GM, CFU-Meg, CFU-Eo, CFU-osteoclasts and CFU-blasts) in human bone marrow. CD34 is the earliest marker of colony building cells in bone marrow. The molecule is heavily glycosylated in the N-terminal extracellular region and therefore sensitive to neuraminidase (target of CD34 class I antibodies). This region is followed by a globular Cys-rich domain. The cytoplasmic portion of the molecule contains sites for proteinkinase C and tyrosine phosphorylation. Human CD34 antigen (Epitope neuraminidase resistant , glycoprotease- and chymopapain-sensitive).