Thermo Fisher Scientific CD8a Monoclonal Antibody (4SM15), eBioscience

Applications and Tested Dilutions

Product Specifications

Additional Formats

• Biotin
• Request custom conjugation

Product Specific Information

The 4SM15 monoclonal antibody reacts with the mouse CD8a molecule, a 32–34 kDa cell surface receptor expressed as either a heterodimer with CD8 beta (CD8αβ) or a homodimer (CD8αα). Most thymocytes and a subpopulation of mature αβ TCR T cells express CD8αβ, while γδ TCR T cells, intestinal intraepithelial lymphocytes (IELs), and dendritic cells express CD8αα. CD8 binds to MHC class I and, through association with p56lck, plays a role in T cell development and activation.

Recent studies show that the 4SM15 antibody recognizes a non-CD8a epitope in neural tissue; therefore, it is not recommended for staining mouse neural tissue. For FFPE mouse neural tissue detection, use Anti-Mouse CD8a Purified, Product #14-0195.

The 4SM15 antibody is not recommended for frozen mouse tissue IHC. For that application, use Anti-Mouse CD8a Purified, Product #14-0081-82.

Applications Reported: Flow cytometry, microscopy, and IHC of formalin-fixed paraffin-embedded (FFPE) tissue sections.
Applications Tested:

• IHC (FFPE mouse tissue): ≤5 µg/mL
• Flow cytometry (mouse splenocytes): ≤0.25 µg/test (100 µL final volume)

Purity: >90% (SDS-PAGE)
Aggregation: <10% (HPLC)
Filtration: 0.2 µm post-manufacturing filtered

Target Information

Cluster of differentiation 8 (CD8) is a type I transmembrane glycoprotein of the immunoglobulin receptor family, essential for signal transduction and T cell differentiation/activation. CD8 is primarily expressed as a CD8αβ heterodimer on T cells, functioning as a co-receptor with TCR for MHC-I molecules. CD8α also forms homodimers on subsets of T cells, NK cells, monocytes, and dendritic cells. Engagement with MHC-I/peptide complexes recruits Lck kinase, leading to cytokine production, motility, and cytotoxic T lymphocyte (CTL) activation. Activated CTLs are critical for pathogen and tumor cell clearance. Differentiation of naive CD8+ T cells into CTLs is enhanced by IL-2, IL-12, and TGF-β1.

For Research Use Only. Not for use in diagnostic procedures. Not for resale without express authorization.