All IHC stains will include a positive control tissue

• Intended for the identification of cells of B-cell lineage (reacts with 97% of B-cell neoplasms) [see Table 1]
• Staining is consistently strong on small cell neoplasm, but large B-cell neoplasms and follicular lymphomas show weaker staining²
• Normal plasma cells will stain intensely with CD79a
• 50% of myelomas show CD79a positivity²
• CD79a is found in the majority (89%) of acute leukemias of precursor B-cell type, in B-cell lines but not in T-cell lines¹
• Most reliable B-cell marker detectable in paraffin embedded specimens in precursor B-cell ALL²
• CD79a is specifically associated with bi-phenotypic leukemias that express myeloid and B-cell antigens and have heavy chain genes in rearranged configurations. Along with CD-22, it is more useful than other B-cell antigens in detecting bi-phenotypic cases within AML
• CD79a is an improvement on L26(CD-20) which labels dendritic reticulum cells, some T-cells and reacts with neoplastic cells in cases of AML²
• CD20 is not expressed until the late precursors B-cell stage and at least half of precursor B ALL's are CD-20 negative³
• Occasional Reed Sternberg cells in cases of Hodgkin's disease are CD79a positive ^{4 & 5}

Table 1 (Ref 2)
Reactivity of Anti-CD79a (mb-1) antibody JCB117 with paraffin-embedded samples of Hematopoietic Neoplasms