CD8 is a cell surface receptor expressed either as a heterodimer with the beta chain or as a homodimer. A majority of thymocytes and a subpopulation of mature Tcells and NK cells express CD8a. It binds to MHC class 1 and through its association with protein tyrosine kinase p56lck plays a role in Tcell development and activation of mature Tcells. For mature Tcells, CD8 and 4 are mutually exclusive, so antibody to CD8 is generally used in conjunction with antibody to CD4. CD8a antibody is a useful marker for distinguishing helper/inducer T-lymphocytes, and most peripheral Tcell lymphomas are CD4+/CD8-. Anaplastic large cell lymphoma is usually CD4+/CD8-, and in T-lymphoblastic lymphoma/leukemia, they are often co-expressed. It is also found in littoral cell angioma of the spleen.

The concentration stated for each application is a general starting point.Variations in protocols, secondaries and substrates may require the CD8 antibody to be titered up or down for optimal performance.

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.

A 13 amino acid peptide from the C-terminal cytoplasmic domain of the alpha chain was used as immunogen for this CD8 antibody.

CD8 antibody with azide can be stored at 2-8oC. The azide-free format should be aliquoted and stored at -20oC or colder.