CD45 Monoclonal Antibody (Clone BRA-55)

CD45 is a type I transmembrane glycoprotein that is encoded by the PTPRC gene in humans and is abundantly expressed on nucleated hematopoietic cells.{49671} It contains an extracellular region that binds to glycoproteins and exists in various isoforms in a cell type-, differentiation state-, and activation state-dependent manner.{49671,49676} CD45 also contains two highly conserved cytoplasmic protein tyrosine phosphatase domains that regulate intracellular signaling.{49671} CD45 functions as a negative or positive regulator of antigen receptor signaling in T and B cells through dephosphorylation of Src family kinases in a cell type- and differentiation state-dependent manner.{49676} It also dephosphorylates JAK kinases, inhibiting cytokine and chemokine signaling in leukocytes. Mutations in PTPRC are associated with severe combined immunodeficiency (SCID) in mice and humans.{49672,49673,49674} The number of CD45+ cells is increased in postmortem brain from patients with Alzheimer's disease.{49675} Increased levels of the CD45 isoform CD45RO have been found on CD19+ lamina propria B cells isolated from patients with Crohn's disease.{49676} Fluorescently labeled versions of CD45 have commonly been used in flow cytometry as a pan leukocyte marker and to identify certain subsets of hematopoietic stem cells (HSCs).{59858} Cayman's CD45 Monoclonal Antibody (Clone BRA-55) can be used for flow cytometry (FC), immunocytochemistry (ICC), immunohistochemistry (IHC), and Western blot (WB) applications. The antibody recognizes CD45 at approximately 170 to 220 kDa from human samples.