Recognizes a 180-185 kDa protein, identified as isoform of leukocyte common antigen (CD45RO) (4th Leucocyte Typing Workshop: Code No. N31). The epitope recognized by this antibody is sensitive to neuraminidase digestion. This antibody reacts with mature activated T-cells, most thymocytes, and a sub-population of resting T-cells within both CD4 and CD8 subsets. It shows no reactivity with normal B or natural killer cells, but reacts with granulocytes and monocytes. Reportedly, it is useful to identify T-cell lymphomas and leukemias. It rarely stains NK cells or B-cell lymphomas. Primary antibodies are available purified, or with a selection of fluorescent CF® Dyes and other labels. CF® Dyes offer exceptional brightness and photostability. Note: Conjugates of blue fluorescent dyes like CF®405S and CF®405M are not recommended for detecting low abundance targets, because blue dyes have lower fluorescence and can give higher non-specific background than other dye colors.