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 beta chain (CD8 alpha beta) or as a homodimer (CD8 alphaalpha). 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: This OKT8 antibody has been reported for use in flow cytometric analysis.
Applications Tested: This OKT8 antibody has been pre-diluted and tested by flow cytometric analysis of normal human peripheral blood cells. This may be used at 5 µL (0.125 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 10^5 to 10^8 cells/test.
Super Bright 645 is a tandem dye that can be excited with the violet laser line (405 nm) and emits at 645 nm. We recommend using a 660/20 bandpass filter. Please make sure that your instrument is capable of detecting this fluorochrome.
When using two or more Super Bright dye-conjugated antibodies in a staining panel, it is recommended to use Super Bright Complete Staining Buffer (Product # SB-4401) to minimize any non-specific polymer interactions. Please refer to the datasheet for Super Bright Staining Buffer for more information.
Light sensitivity: This tandem dye is sensitive to photo-induced oxidation. Please protect this vial and stained samples from light.
Fixation: Samples can be stored in IC Fixation Buffer (Product # 00-8222) (100 µL of cell sample + 100 µL of IC Fixation Buffer) or 1-step Fix/Lyse Solution (Product # 00-5333) for up to 3 days in the dark at 4°C with minimal impact on brightness and FRET efficiency/compensation. Some generalizations regarding fluorophore performance after fixation can be made, but clone specific performance should be determined empirically.
Excitation: 405 nm; Emission: 645 nm; Laser: Violet Laser
Super Bright Polymer Dyes are sold under license from Becton, Dickinson and Company.
CD8 (Cluster of Differentiation 8) is a cell surface glycoprotein found on most cytotoxic T lymphocytes that mediate efficient cell-cell interactions within the immune system. The CD8 antigen acts as a co-receptor with the T-cell receptor on the T lymphocyte to recognize antigens displayed by an antigen presenting cell (APC) in the context of class I MHC molecules. CD8 is found on a T cell subset of normal cytotoxic/suppressor cells which make up approximately 20-35 % of human peripheral blood lymphocytes. The CD8 antigen is also detected on natural killer (NK) cells, subpopulations of peripheral blood null cells, thymocytes and bone marrow cells. The CD8 co-receptor functions as either a homodimer composed of two alpha chains, or as a disulfide-linked heterodimer composed of one alpha and one beta chain. Both alpha and beta chains share significant homology to immunoglobulin variable light chains. The majority of CD8+ T cells express CD8 as a alpha/beta heterodimer. In HIV, the HIV-2 envelope glycoprotein binds CD8 alpha chain (but not the beta chain).
For Research Use Only. Not for use in diagnostic procedures. Not for resale without express authorization.
Protein Aliases: CD8 antigen, alpha polypeptide (p32); CD8a; Leu2 T-lymphocyte antigen; OKT8 T-cell antigen; T cell co-receptor; T-cell antigen Leu2; T-cell surface glycoprotein CD8 alpha chain; T-lymphocyte differentiation antigen T8/Leu-2; T8 T-cell antigen
Gene Aliases: CD8; CD8A; Leu2; MAL; p32
UniProt ID: (Human) P01732
Entrez Gene ID: (Human) 925