Anti-Human CD45 [Clone 2B11] - FITC (C3114-50ug)

CD45 is a 180-240 kDa glycoprotein member of the protein tyrosine phosphatase (PTP) family known for its involvement in regulating a variety of cellular processes including cell growth, differentiation, mitotic cycle, and oncogenic transformation. CD45 and its isoforms are vital regulators of T- and B-cell antigen receptor signaling. It functions through its extracellular domain or through its cytoplasmic domain and serves as a negative regulator of cytokine receptor signaling via JAK kinase suppression. The large extracellular domain is highly glycosylated, and its multiple isoforms allow extensive variation in the structure of its side chains. CD45 isoforms show cell-type and differentiation-stage specific expression that can be used as markers that identify and distinguish between different types of immune cells. CD45R is an isoform of CD45 with a molecular weight of 220 kDa. CD45R contains all three possible exons (A, B, and C), making it the longest protein generated from alternative splicing with a migration at 200 kDa when isolated from T cells. Furthermore, B cells express CD45R with heavier glycosylation, bringing the molecular weight to 220 kDa, hence the name B220. Notably, B220 expression is not restricted to B cells and may be expressed on activated T cells, on a subset of dendritic cells, and on other antigen-presenting cells. Additionally, activated and memory T lymphocytes express CD45RO which facilitates T cell activation. CD45RO lacks all three possible exons (A, B, and C), making it the shortest CD45 isoform. 2B11 was originally generated as against leukocyte common antigen1. Isolated neoplastic cells from T cell lymphoma were used as and immunogen for 2B11. 2B11 stains most T cell and B cell lymphomas but not Reed-Sternberg cells or variants of Hodgkin's disease2. 2B11 also stains osteoclasts3 and has been tested in the pathology setting and can be used to distinguish neoplasms4-9.