Sigma-Aldrich Anti-Cd8 Clone Sk1 100 Mig

T-cell surface glycoprotein CD8 alpha chain (UniProt: P01732; also known as T-lymphocyte differentiation antigen T8/Leu-2, CD8a) is encoded by the CD8A (also known as MAL) gene (Gene ID: 925) in human. CD8 alpha is a single-pass type I membrane glycoprotein that is synthesized with a signal peptide (aa 1-21), which is subsequently cleaved to produce the mature protein that has an extracellular domain (aa 22-182), a helical domain (aa 183-203), and a cytoplasmic tail (aa 204-235). CD8 is generally present as a heterodimer of and β chains linked by two disulfide bonds, however, it can also form homodimers. The CD8 / homodimer is expressed on a subset of / TCR-bearing T cells, NK cells, intestinal intraepithelial lymphocytes, and lymphoid dendritic cells. CD8a homodimer is reported to promote the survival and differentiation of activated lymphocytes into memory CD8 T-cells. CD8a plays an essential role in the immune response and serves multiple functions in responses against both external and internal offenses. In T-cells, it functions primarily as a co-receptor for MHC class I molecule:peptide complex. It interacts simultaneously with the T-cell receptor (TCR) and the MHC class I proteins presented by antigen presenting cells. In turn, it recruits the Src kinase LCK to the vicinity of the TCR-CD3 complex where LCK phosphorylates various substrates leading to lymphokine production, motility, adhesion, and activation of cytotoxic T-lymphocytes (CTLs). This process enables CTLs to recognize and eliminate infected cells and tumor cells. Mutations in CD8A gene are known to cause the absence of CD8+ cells leading to recurrent bacterial infections. The Anti-CD8, clone SK1 mouse monoclonal antibody is specific for the 32-34 kDa alpha chain of human CD8, known as CD8a or CD8 alpha. Sheep erythrocyte rosetting of human peripheral blood lymphocytes is a phenomenon where human T lymphocytes adhere to sheep red blood cells (SRBC), forming a rosette-like structure. (Ref.: Harland, KL., et Al., (2014). Nat. Commun. 5; Article 3547; Gibbings, DJ., et Al. (2007). BMC Immunol. 8; 12; de la Calle-Martin, O., et Al. (2001). J. Clin. Invest. 108(1); 117-123).

Sheep-erythrocyte-rosetting human peripheral blood lymphocytes.

Quality Control Testing

Evaluated by Flow Cytometry in human peripheral blood mononuclear cells (PBMC).

Flow Cytometry Analysis: 1.0 µg from a representative lot detected CD8 in one million human peripheral blood mononuclear cells (PBMC).

Tested Applications

Activity Assay: A representative lot detected CD8 in Activity Assay (Sanjurjo, L., et Al. (2021). Commun. Biol. 4(1):1415).

Flow Cytometry Analysis: A representative lot detected CD8 in Flow Cytometry applications (Evans, R.L., et Al. (1981). Proc Natl Acad Sci USA. 78(1):544-8).

Immunohistochemistry Applications: A representative lot detected CD8 in Immunohistochemistry applications (Tjin, E.P.M., et Al. (2014). Cancer Immunol Res. 2(6):538-46).

Note: Actual optimal working dilutions must be determined by end user as specimens, and experimental conditions may vary with the end user.

Clone SK1 is a mouse monoclonal antibody that detects CD8. It targets an epitope from the extracellular domain.

Purified mouse monoclonal antibody IgG1 in buffer containing 0.1 M Tris-Glycine (pH 7.4), 150 mm NaCl with 0.05% sodium azide.

0.5 mg/mL. Please refer to guidance on suggested starting dilutions and/or titers per application and sample type.

Recommended storage: +2°C to +8°C.

Concentration: Please refer to the Certificate of Analysis for the lot-specific concentration.

Unless otherwise stated in our catalog or other company documentation accompanying the product(s), our products are intended for research use only and are not to be used for any other purpose, which includes but is not limited to, unauthorized commercial uses, in vitro diagnostic uses, ex vivo or in vivo therapeutic uses or any type of consumption or application to humans or animals.