Alexa Fluor® 647 Mouse Anti-Rat CD45 Antibody (S-R591)

CD45 (also known as protein tyrosine phosphatase receptor type C, PTPRC, or leukocyte common antigen) is a type I transmembrane glycoprotein tyrosine phosphatase expressed on all nucleated hematopoietic cells except erythrocytes and plasma cells, serving as a critical regulator of T- and B-cell antigen receptor signaling through modulation of Src-family kinases and other key signaling molecules by dephosphorylating specific tyrosine residues, thereby influencing immune cell activation and differentiation; it exists in multiple isoforms generated via alternative splicing of its extracellular domain, enabling discrimination of immune cell subsets and stages of activation, and its dysregulation is implicated in immunodeficiency, autoimmunity, and malignancies.