CD34 PE-Cyanine7

CD34, also known as gp105-120, is a type I monomeric sialomucin-like glycophosphoprotein with a molecular weight of approximately 105-120 kDa. It is primarily expressed on hematopoietic stem and progenitor cells, bone marrow stromal cells, capillary endothelial cells, embryonic fibroblasts, and certain nervous tissues. CD34 is widely used as a marker to identify human hematopoietic stem and progenitor cells. Its expression varies with differentiation stages, being highly expressed on early progenitor cells and gradually decreasing as cells mature, eventually becoming absent in fully differentiated hematopoietic cells. Functionally, CD34 plays a role in cell adhesion and lymphocyte homing by binding to L-selectin and E-selectin ligands. It is found on all hematopoietic colony-forming cells in bone marrow and blood, including both unipotent (CFU-GM, BFU-E) and pluripotent progenitors (CFU-GEMM, CFU-Mix, and CFU-Blast). CD34+ cells that are uncommitted lack lineage-specific markers such as CD71, CD33, CD10, and CD5, whereas lineage-committed CD34+ cells express CD38 at high levels. Additionally, most CD34+ cells express either CD45RO or CD45RA, with CD45RO+ cells being the more primitive subset. CD34 is also present on early myeloid cells expressing CD33 but lacking CD14 and CD15, as well as early erythroid cells that express CD71 and dimly express CD45.  It is absent in normal peripheral blood lymphocytes, monocytes, granulocytes, and platelets. Clinically, CD34 is expressed in approximately 60% of acute B-lymphoid leukemias and acute myeloid leukemias (AML), as well as in a small percentage (1-5%) of acute T-lymphoid leukemias. However, it is not found in chronic lymphoid leukemias or lymphomas.