CD8 is a cell surface receptor expressed either as a heterodimer with the CD8 beta chain (CD8a/b) or as a homodimer (CD8a/a). A majority of thymocytes and a subpopulation of mature T cells and NK cells express CD8a. CD8 binds to MHC class 1 and through its association with protein tyrosine kinase p56lck plays a role in T cell development and activation of mature T cells. For mature T-cells, CD4 and CD8 are mutually exclusive, so anti-CD8, generally used in conjunction with anti-CD4. It is a useful marker for distinguishing helper/inducer T-lymphocytes, and most peripheral T-cell lymphomas are CD4+/CD8-. Anaplastic large cell lymphoma is usually CD4+ and CD8-, and in T-lymphoblastic lymphoma/leukemia, CD4 and CD8 are often co-expressed. CD8 is also found in littoral cell angioma of the spleen.

The optimal dilution of the CD8a antibody for each application should be determined by the researcher.

1. Staining of formalin-fixed tissues requires boiling tissue sections in 10mM citrate buffer, pH 6.0, for 10-20 min followed by cooling at RT for 20 minutes.2. The prediluted format is supplied in a dropper bottle and is optimized for use in IHC. After epitope retrieval step (if required), drip mAb solution onto the tissue section and incubate at RT for 30 min.

Human recombinant protein (C8/468) and13 amino acid peptide from the C-terminal cytoplasmic domain of the alpha chain of human CD8 (C8/144B) were used as the immunogens for this CD8a antibody cocktail.

Store the CD8a antibody cocktail at 2-8oC (with azide) or aliquot and store at -20oC or colder (without azide).