The mAb I3/2.3 recognizes mouse CD45, which is also known as the leukocyte common antigen (L-CA or LCA), T200, or Lymphocyte antigen 5 (Ly-5). CD45 is a 180-240 kDa single-pass type I transmembrane glycoprotein that is encoded by Ptprc (protein tyrosine phosphatase, receptor type, C) which belongs to the protein tyrosine phosphatase (PTP) family. CD45 is variably expressed on thymocytes and other hematopoietic cells except mature erythrocytes and platelets. Different isoforms of CD45 arise from alternative splicing of variable exons 4, 5, and 6, which encode A, B, and C determinants, respectively, that encode extracellular domains of the transmembrane receptor. The differential expression of these isoforms is related to the cell's lineage as well as its state of activation and maturation. The mAb I3/2.3 reportedly recognizes all CD45 isoforms. CD45 plays key roles as a protein tyrosine-protein phosphatase in leucocyte responses including signal pathways transduced by antigen specific receptors expressed on T cells (TCRs) and B cells (BCRs).
The antibody was conjugated to BD Horizon BUV395 which has been exclusively developed by BD Biosciences as an optimal dye for use on a 355 nm laser equipped instrument. With an Ex Max at 348 nm and an Em Max at 395 nm, this dye has virtually no spillover into any other detector. BD Horizon BUV395 can be excited with a 355 nm laser and detected with a 379/28 filter.