CD45R Rat anti-Murine, Brilliant Ultraviolet 496, Clone: RA3-6B2, BD Horizon™

Description

• The rat anti-mouse CD45R antibody (clone RA3-6B2) has been reported to react with an epitope on the extracellular domain of the transmembrane CD45 glycoprotein which is dependent upon the expression of exon A and specific carbohydrate residues
• It is expressed on B lymphocytes at all stages from pro-B through mature and activated B cell, but it is decreased on plasma cells and a subset of memory B cells
• The levels of CD45R expression on the B-cell lineage appear to be developmentally regulated
• It is also reportedly found on the abnormal T cells involved in the lymphadenopathy of lpr/lpr and gld/gld mutant mice, on lytically active subsets of lymphokine-activated killer cells (NK cells and non-MHC-restricted CTL), on apoptotic T lymphocytes of mice injected with bacterial superantigen, on a population of NK-cell precursors in the bone marrow, and on B-lymphocyte, T-lymphocyte, and macrophage progenitors in fetal liver
• The CD45R antigen has been reported not to be on hematopoietic stem cells, naive T lymphocytes, or MHC-restricted CTL
• CD45 is a member of the Protein Tyrosine Phosphatase (PTP) family: Its intracellular (COOH-terminal) region contains two PTP catalytic domains, and the extracellular region is highly variable due to alternative splicing of exons 4, 5, and 6 (designated A, B, and C, respectively), plus differing levels of glycosylation
• The CD45 isoforms detected in the mouse are cell type-, maturation, and activation state-specific
• The CD45 isoforms play complex roles in T-cell and B-cell antigen receptor signal transduction
• CD45R is commonly used as a pan B-cell marker; however, CD19 expression, detectable by the rat anti-mouse CD19 antibody (clone 1D3), is reported to be more restricted to the B-cell lineage
• The rat anti-mouse CD45R antibody (clone RA3-6B2) has been reported to enhance isotype switching during in vitro B-cell responses and to inhibit in vivo B-cell responses
• Cross-reaction of the RA3-6B2 clone with activated human T lymphocytes has also been reportedly observed
• The antibody was conjugated to BD Horizon BUV496 which is part of the BD Horizon Brilliant™ Ultraviolet family of dyes
• This dye is a tandem fluorochrome of BD Horizon BUV395 with an Ex Max of 348-nm and an acceptor dye with an Em Max at 496-nm
• BD Horizon BUV496 can be excited by the ultraviolet laser (355 nm) and detected with a 515/30nm filter with a 450LP
• Due to the excitation of the acceptor dye by other laser lines, there may be significant spillover into the channel detecting BD Horizon V500 or BV510 (e.g., 525/40-nm filter)
• However, the spillover can be corrected through compensation as with any other dye combination.