Protein Overview
CD8A encodes the alpha chain of the CD8 co-receptor on cytotoxic T lymphocytes, existing as a CD8αα homodimer or CD8αβ heterodimer. It binds MHC class I on target cells, stabilizing the TCR-peptide-MHC interaction and recruiting the Src-family kinase LCK, lowering the activation threshold for cytotoxic T cell responses.
Expected Localization
Plasma membrane, type I transmembrane glycoprotein with a short cytoplasmic tail.
Expected pattern is crisp membranous/surface staining outlining individual lymphocytes, with no significant nuclear or diffuse cytoplasmic signal.
Expected Expression Pattern
Expressed on cytotoxic/suppressor T cells, a subset of NK cells, and most CD8+ thymocytes; found in blood, spleen, lymph node, tonsil, and thymus. Expression level and dimer composition vary with activation/differentiation state.
Relevant Pathways
- TCR-MHC class I recognition and antigen presentation
- Immune synapse formation
- LCK/Src-family kinase recruitment and proximal TCR signaling
- ZAP70/ITAM-mediated signal transduction
- Thymocyte positive/negative selection
- Cytotoxic T lymphocyte-mediated killing
Clone Information
Antibody Species: Rabbit
Cell Type Compatibility: Validated in human cells only using Cytos™ kits.
For more details on the clone and reactivity with other species, visit ABclonal and search for the clone catalog # A23305PMBCS.
Qualitative Results
Localization Assessment
CD8A protein panel demonstrates strong localization to the cell membrane of a subpopulation of PBMCs. The observed localization of CD8A protein in a subpopulation of PBMC cells is consistent with published data. Not tested in a CD8A-positive tissue or cell line (such as engineered CD8+ Jurkat cell models).
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| PBMC |
PBMCs were cultured independently in flasks, spun down to a 12-well format following the user guide for suspension cells, fixed with 4% formaldehyde for 30 minutes, and permeabilized using 70% ethanol for 10 minutes. Cells were then incubated with probe made with biotinylated Rabbit monoclonal anti-CD8A antibody for 1 hour at room temperature. The slide kit was then assembled into a flow cell and loaded onto an AVITI24™ along with the Cytos Protein Cartridge for a multiomics cell screening run. CD8A demonstrated enhanced expression in a fraction of PBMCs, and no obvious expression in Jurkat and Raji cells. These results support high confidence in target-specific detection and validate this antibody as a passing clone.
Quantitative Results
| Signal-to-noise ratio Acceptance criteria: > 2x background |
Pass |
- 4.88 ± 2.18 (PBMC; n=3 runs)
Indicates the fold brightness of the target signal as measured by the Mean Intensity Above (Otsu-defined) Threshold (IAT), over the background (a channel-matched isotype control) in the same cell. The result of 2.36 in PBMCs exceeds the acceptance threshold, though by a narrower margin than most targets in the panel; signal is confined to the expected CD8A-positive subpopulation.
|
Panel-level run-to-run reproducibility |
Pass |
For each imaging panel, we assess reproducibility by comparing the intensity signal a given antibody target produces across independent replicate runs. Within each run, we measure the average per-well fluorescence intensity for every target in the panel. We then plot each target's intensity from one run against the matching target's intensity from another run of the same layout, and calculate the Pearson correlation coefficient (r) between those two sets of measurements. Squaring that value gives the R² (coefficient of determination), which reports what fraction of the variation in one run's signal is explained by the other run's signal.
Disclaimer: This information is provided to help assess whether the target suits your experiment. It reflects internal testing conditions and does not guarantee performance in your application. Performance in other cell types and species such as mouse or rat may require additional validation using Cytos kits as performance is not guaranteed.
ELEMENT BIOSCIENCES For Research Use Only. Not for Use in diagnostic procedures.