Sigma-Aldrich Anti-Cd8 Clone Sk1 25 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.

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