APC Rabbit anti-Human CD81 Monoclonal Antibody for Flow Cytometry - P60033

Core Product Specifications and Parameters

Biological Background: CD81 Function and Localization

• CD81 (also known as TAPA-1 or Tspan28) is a 26 kDa tetraspanin containing multiple transmembrane domains and a conserved disulfide bond, functioning as a structural component of specialized membrane microdomains.
• On activated B cells, CD81 organizes tetraspanin-enriched microdomains (TERMs) essential for CD19 trafficking and compartmentalization, thereby lowering the threshold for B cell receptor (BCR)-mediated activation and antibody production. Related references: PMID:16449649, PMID:20237408, PMID:27881302, PMID:15161911
• In T cells, CD81 facilitates localization of CD3 zeta at immunological synapses, contributing to costimulation and polarization toward a T helper type 2 phenotype. Related references: PMID:22307619, PMID:23858057, PMID:8766544
• Present in MHC class II compartments, CD81 may also play a role in antigen presentation. Related references: PMID:8409388, PMID:8766544
• CD81 negatively regulates macrophage fusion into multinucleated giant cells by associating with CD9 and beta-1/beta-2 integrins. Related references: PMID:12796480
• In T cells, CD81 controls intracellular dNTP levels by directing proteasomal degradation of the dNTPase SAMHD1. Related references: PMID:28871089
• CD81 acts as a critical receptor for hepatitis C virus (HCV) entry into hepatocytes, forming a complex with claudin-1 (CLDN1). It is also specifically required for Plasmodium falciparum sporozoite infectivity of human liver cells.
• Subcellularly, CD81 localizes to the cell membrane, particularly the basolateral region. It is expressed on B cells, hepatocytes, monocytes/macrophages, and both naïve and memory CD4+ T cells.

Experimental Guidance and Technical Tips

• The immunogen corresponds to the large extracellular loop (LEL, amino acids 114-199) of human CD81, a domain involved in ligand binding and viral interactions; antibodies targeting this region may recognize native conformations and are often suitable for surface staining in flow cytometry.
• For flow cytometry, titrate the APC conjugate to optimize the signal-to-noise ratio, using known positive (e.g., peripheral blood B cells or CD81-transfected lines) and negative controls to establish gating.
• Due to the broad expression of CD81 on leukocytes and hepatocytes, include appropriate isotype controls and consider dual staining with lineage markers to accurately assess cell-type-specific expression.
• If using this antibody to study CD81-mediated viral entry or receptor clustering, validate in the relevant sample system (e.g., primary hepatocytes or B cell lines) under activation conditions to ensure proper detection.

CamelBio: Your One-Stop Sourcing Bridge

CamelBio supports diagnostic manufacturers and research laboratories with comprehensive access to IVD raw materials, including validated monoclonal antibodies like this anti-CD81 APC conjugate. Whether you require customized antibody pairs, bulk ancillary reagents, or assistance sourcing rare targets for immunology and infectious disease applications, CamelBio provides a streamlined procurement pathway from concept to clinic. Our team can help you secure consistent, high-quality raw materials to advance your CD81-related diagnostic or research projects.