Recognizes a non-polymorphic determinant of DP-MHC class II. MHC class II antigens are transmembrane glycoproteins of non-covalently linked alpha (33-35 kDa) and beta (27-30 kDa) chains. It reportedly reacts with B- non-T, non-B cell lines but not with T- and myeloid cell lines and leukemias. Differential expression of MHC class II antigens on fetal and adult lymphocytes, malignant B cells appears to reflect the stage of cell differentiation which may be useful in the study of lymphoproliferative disorders. 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.