Bcl-6 is a transcriptional repressor mainly required for germinal center (GC) formation and antibody affinity maturation which has different mechanisms of action specific to the lineage and biological functions. It forms complexes with different corepressors and histone deacetylases to repress the transcriptional expression of different subsets of target genes. Bcl-6 allows GC B-cells to proliferate very rapidly in response to T-cell dependent antigens and tolerate the physiological DNA breaks required for immunglobulin class switch recombination and somatic hypermutation without inducing a p53/TP53-dependent apoptotic response. Antibodies to Bcl-6 are helpful in a number of diagnostic settings, for example in the differential diagnosis of small B-cell lymphoma, and in distinguishing classical Hodgkin lymphoma from nodular lymphocyte predominant Hodgkin lymphoma (NLPHL). 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.