CD45R, also known as B220, is the longest isoform of CD45, with a glycosylation pattern resulting in a molecular weight of 220 kDa. B cells at all developmental stages express CD45R, as do subsets of T, NK, and dendritic cells. In mice, CD45R has been historically used as a pan-B cell marker. However, CD19 offers greater specificity for the B cell lineage.
Anti-Mouse CD45R/B220 (RA3-6B2)-160Gd—100 Tests