Staining of normal human peripheral blood cells with Mouse IgG2a K Isotype Control Purified (cat. 14-4724) (open histogram) or 0.125 µg of Anti0Human CD8 Purified (filled histogram) followed by Anti-Mouse IgG FITC (cat. 11-4011). Cells in the lymphocyte gate were used for analysis.
*Functional Grade™ (FG™) Purified: Azide-free, sterile-filtered, and endotoxin < 0.001 ng/µg (unless otherwise noted). *Functional Grade™ (FG™) Biotin: Azide-free, sterile-filtered, and endotoxin < 0.05 ng/µg. Purified: Contains azide, not sterile-filtered, and not endotoxin tested.
Flow Cytometry Product Notes: Test Sizes: To accommodate multicolor flow cytometry, eBioscience is in the process of reducing test size volumes from 20 µl to 5 µl. Please check your antibody vial for the recommended test size. Fluorochrome Replacements: eBioscience is in the process of replacing all Alexa Fluor® 647 conjugated products with eFluor® 660 conjugated products.
Description
The OKT8 monoclonal antibody reacts with the human CD8a molecule, an approximately 32-34 kDa cell surface receptor expressed either as a heterodimer with the CD8 β chain (CD8 αβ) or as a homodimer (CD8 αα). A majority of thymocytes and a subpopulation of mature T cells and NK cells express CD8a. CD8 binds to MHC class I and through its association with protein tyrosine kinase p56lck plays a role in T-cell development and activation of mature T cells. Preliminary testing indicates that OKT8 and two other mouse anti-human CD8 antibodies (clone RPA-T8, Cat. No.14-0088 and clone HIT8a, Cat. No.14-0089) do not compete with each other for binding to human peripheral blood leukocytes by flow cytometric analysis, suggesting that they do not bind to similar epitopes or block each other by steric hindrance.
Applications Reported
For research use only, not for diagnostic or therapeutic use. The OKT8 (OKT-8) antibody has been reported for use in flow cytometric analysis.
Applications Tested
This OKT8 (OKT-8) antibody has been tested by flow cytometric analysis of human peripheral blood leukocytes. This can be used at less than or equal to 0.25 μg per test. A test is defined as the amount (μg) of antibody that will stain a cell sample in a final volume of 100 µL. Cell number should be determined empirically but can range from 105 to 108 cells/test. It is recommended that the antibody be carefully titrated for optimal performance in the assay of interest.
References
Kay HD, Horwitz DA. 1980. Evidence by reactivity with hybridoma antibodies for a probable myeloid origin of peripheral blood cells active in natural cytotoxicity and antibody-dependent cell-mediated cytotoxicity. J Clin Invest. 66(4):847-51.
Sayos J, Wu C, Morra M, Wang N, Zhang X, Allen D, van Schaik S, Notarangelo L, Geha R, Roncarolo MG, Oettgen H, De Vries JE, Aversa G, Terhorst C.The X-linked lymphoproliferative-disease gene product SAP regulates signals induced through the co-receptor SLAM. Nature. 1998 Oct 1;395(6701):462-9. (OKT8, IP, PubMed)
Thomas Y, Sosman J, Irigoyen O, Friedman SM, Kung PC, Goldstein G, Chess L. 1980. Functional analysis of human T cell subsets defined by monoclonal antibodies. I. Collaborative T-T interactions in the immunoregulation of B cell differentiation. J Immunol. 125(6):2402-8.
Campanelli R, Palermo B, Garbelli S, Mantovani S, Lucchi P, Necker A, Lantelme E, Giachino C. 2002. Human CD8 co-receptor is strictly involved in MHC-peptide tetramer-TCR binding and T cell activation. Int Immunol. 14(1):39-44.
