| Field | Specification |
|---|---|
| Mfr No | |
| Accession Number | |
| Alternative Names | Tetraspanin-28, TSPAN28, Target of the Antiproliferative Antibody 1, TAPA-1 |
| Clonality | |
| Conjugate | |
| Host | |
| Isotype | |
| Product Type | |
| Reactivity | |
| Shipping | |
| Storage | |
| Target |
Overview
Anti-CD81 (extracellular)-FITC Antibody is an antibody targeting Tetraspanin-28, TSPAN28, Target of the Antiproliferative Antibody 1, TAPA-1 Polyclonal raised in Rabbit (Fluorescein isothiocyanate (FITC)). This antibody is commonly used in FC, LCI to detect, localize, or compare expression of the target across samples.
Key elements and design rationale
- Target: Tetraspanin-28, TSPAN28, Target of the Antiproliferative Antibody 1, TAPA-1 (also reported as Tetraspanin-28, TSPAN28, Target of the Antiproliferative Antibody 1, TAPA-1).
- Immunogen/epitope region: Extracellular, 2nd loop..
- Homology note: Mouse, rat - 11 out of 12 amino acid residues identical (informative for cross-species interpretation).
- Species reactivity (as provided): Human, Rat, Mouse.
- Lot quality control (as provided): Western blot analysis (unlabeled antibody, #ANR-211), and direct flow cytometry (labeled antibody)..
- Peptide confirmation: Confirmed by amino acid analysis and mass spectrometry.
- Blocking peptide: Available for antigen preadsorption control where appropriate.
- Conjugate/format: Fluorescein isothiocyanate (FITC) (may affect detection channel and background).
These attributes help researchers interpret whether signal reflects the intended target in a given assay and sample context.
Biological background
Cluster of differentiation 81, CD81, also known as Tetraspanin-28, Tspan28, and target of the antiproliferative antibody 1, TAPA-1, is a transmembrane (TM) protein, member of the tetraspanin family, and plays a role in intercellular interactions and cellular trafficking.1CD81 is composed of 236 amino acids, four TM regions, intracellular N- and C-termini, small (EC1) and large (EC2) extracellular loops, a short intracellular loop between TM2 and TM3, and is characterized by a bound cholesterol molecule in an intramembrane pocket between the two pairs of TM helices capped by the EC2 domain. The binding of cholesterol alters the conformation of the protein, a process which is exploited by certain viruses to enter cells. CD81 serves as a co-receptor for several viruses, including hepatitis C (HCV), human immunodeficiency virus type 1 (HIV-1), herpes simplex virus 1 (HSV-1), influenza A (IAV), and Chikungunya, as well as certain bacteria and parasites.
Research relevance and current trends
- Profiling immune-marker expression across cell subsets with single-cell or flow-based readouts.
- Connecting receptor/ligand levels to activation state and cytokine programs.
- Applying genetic perturbation or orthogonal assays to support specificity and interpretation.
Common research applications
- Flow cytometry (direct/indirect): quantify target-positive populations and shifts in expression across subsets.
- Live cell imaging (LCI): support extracellular-epitope detection on non-permeabilized cells when appropriate.
Interpretation typically benefits from comparing matched sample sets (e.g., treated vs control, WT vs KO/KD) and using orthogonal readouts where feasible.
Notes for experimental interpretation
- Isoforms and post-translational modifications can shift apparent molecular weight or epitope accessibility across samples.
- Cross-species signal may depend on epitope conservation; consult the provided homology note when selecting models.
- Permeabilization, fixation, and antigen retrieval can change accessibility of intracellular vs extracellular epitopes.
- Conceptual control: antigen preadsorption (blocking peptide) can help assess signal dependence on the immunogen region.
- Provided control suggestions: Negative control: RIC-001-F.
- Application notes: see product-specific dilution/usage notes and control concepts provided in the dataset.
Application abbreviations: CBE- Cell-based ELISA, FC- Flow cytometry, ICC- Immunocytochemistry, IE- Indirect ELISA, IF- Immunofluorescence, IFC- Indirect flow cytometry, IHC- Immunohistochemistry, IP- Immunoprecipitation, LCI- Live cell imaging, N- Neutralization, WB- Western blot. Species abbreviations: H- Human, M- Mouse, R- Rat.
Recommended controls: Blocking peptide: BLP-NR211; Negative control: RIC-001-F.
Customization & Add-ons: Can’t find the antibody you need—or require a custom format for your assay? We can help you source the best match or support custom antibody solutions for diverse research needs, including species and isotype selection, conjugations and labeling (e.g., HRP/AP, biotin, fluorophores), purification grade options (Protein A/G, affinity purified), formulation preferences (buffer selection, carrier-free, glycerol-free), custom concentrations and aliquoting, low-endotoxin options for cell-based work, and application-focused QC/validation support (project dependent). Click Talk to a Scientist to submit a request, email us at support@biohippo.com, or explore our Research Services for additional support—our team will follow up with feasibility details and next steps.
