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

Submit a formalin-fixed, paraffin-embedded tissue

Formalin-fixed, paraffin-embedded (FFPE) tissue block

FFPE tissue section mounted on a charged, unstained slide

Ambient (preferred)

• Unlabeled/mislabeled block
• Insufficient tissue
• Slides broken beyond repair

Immunohistochemical staining and microscopic examination

If requested, an interpretive report will be provided

Specifications

• The mb-1 polypeptide is part of the B-cell antigen receptor complex
• Appears early in B-cell maturation at the pre B-cell stage and persists until the plasma cell stage where it is found as an intracellular component
• Virtually B-cell specific

 Staining pattern

• Cell surface membrane and cytoplasmic

References:

1. Blood, Vol 82(3):853-857, 1993.
2. Blood, Vol 86(4):1453-1459, 1995.
3. AJCP, Vol 106:462-468, 1996.
4. AJSP, Vol 19(11):1294-1299, 1995.
5. Histopathology, 24(6):511-515, 1994.
6. Spec sheet from DAKO.