mouse monoclonal IgG2a; CD8 Antibody (UCH-T4) is an IgG2a κ mouse monoclonal CD8 antibody that detects CD8 of human origin by IP, IF, IHC(P) and FCM. CD8 Antibody (UCH-T4) is available as the non-conjugated anti-CD8 antibody form, as well as multiple conjugated forms of anti-CD8 antibody, including agarose, HRP, PE, FITC and multiple Alexa Fluor® conjugates. The T cell receptor (TCR) is a heterodimer composed of either α and β or γ and δ chains. CD3 chains and the CD4 or CD8 co-receptors are also required for efficient signal transduction through the TCR. The TCR is expressed on T helper and T cytotoxic cells that can be distinguished by their expression of CD4 and CD8; T helper cells express CD4 proteins and T cytotoxic cells display CD8. CD8 (also designated Leu 2 or T8), a cell surface glycoprotein, is a two chain complex (αα or αβ) receptor that binds class I MHC molecules presented by the antigen-presenting cell (APC). A primary function of CD8 is to facilitate antigen recognition by the TCR and to strengthen the avidity of the TCR-antigen interactions. An additional role for CD8-expressing T cells may be to maintain low levels of HIV expression.