Anti-HLA-DR/HLA-DRA Antibody Picoband®

Overview

Anti-HLA-DR/HLA-DRA Antibody Picoband® is an antibody for HLA-DRA detection raised in Rabbit (Polyclonal, Rabbit IgG), with reported reactivity: Human. Commonly used in WB, IHC, Flow Cytometry, ELISA workflows.

Key elements and design rationale

• Target: HLA-DRA (major histocompatibility complex, class II, DR alpha); UniProt: P01903; NCBI Gene: 3122
• Antibody format: Rabbit, Polyclonal, Rabbit IgG
• Molecular weight: 37 kDa, calculated 82536 MW
• Applications: WB, IHC, Flow Cytometry, ELISA

Vendor description (summary): Boster Bio Anti-HLA-DR/HLA-DRA Antibody Picoband® catalog # A01195.

Biological background

Biological context: Binds peptides derived from antigens that access the endocytic route of antigen presenting cells (APC) and presents them on the cell surface for recognition by the CD4 T-cells. The peptide binding cleft accommodates peptides of 10-30 residues. The peptides presented by MHC class II molecules are generated mostly by degradation of proteins that access the endocytic route, where they are processed by lysosomal proteases and other hydrolases. Exogenous antigens that have been endocytosed by the APC are thus readily available for presentation via MHC II molecules, and for this reason this antigen presentation pathway is usually referred to as exogenous. As membrane proteins on their way to degradation in lysosomes as part of their normal turn-over are also contained in the endosomal/lysosomal compartments, exogenous antigens must compete with those derived from endogenous components. Autophagy is also a source of endogenous peptides, autophagosomes constitutively fuse with MHC class II loading compartments. In addition to APCs, other cells of the gastrointestinal tract, such as epithelial cells, express MHC class II molecules and CD74 and act as APCs, which is an unusual trait of the GI tract. To produce a MHC class II molecule that presents an antigen, three MHC class II molecules (heterodimers of an alpha and a beta chain) associate with a CD74 trimer in the ER to form a heterononamer. Soon after the entry of this complex into the endosomal/lysosomal system where antigen processing occurs, CD74 undergoes a sequential degradation by various proteases, including CTSS and CTSL, leaving a small fragment termed CLIP (class-II-associated invariant chain peptide). The removal of CLIP is facilitated by HLA-DM via binding to the alpha-beta-CLIP complex so that CLIP is released. HLA-DM stabilizes MHC class II molecules until primary high affinity antigenic peptides are bound. The MHC II molecule bound to a peptide is then transported to the cell membrane surface. In B-cells, the interaction between HLA-DM and MHC class II molecules is regulated by HLA-DO. Primary dendritic cells (DCs) also to express HLA-DO. Lysosomal microenvironment has been implicated in the regulation of antigen loading into MHC II molecules, increased acidification produces increased proteolysis and efficient peptide loading.

Expression and localization notes: cellular localization: Cytoplasm. Neuron projection..

Common research applications

• Western blotting (WB): Compare HLA-DRA levels across samples and conditions using appropriate loading and biological controls.
• Immunohistochemistry (IHC): Evaluate spatial distribution of HLA-DRA in tissue sections, considering fixation and antigen retrieval effects.
• Flow cytometry: Quantify HLA-DRA-positive populations in single-cell suspensions with appropriate gating and controls.
• ELISA: Use antibody-based detection formats to assess antigen presence or binding in plate-based assays.

Notes for experimental interpretation

• Account for isoforms, post-translational modifications, and sample-specific processing that can shift apparent molecular weight or epitope accessibility.
• Use positive/negative biological controls where possible (e.g., known-expressing cells/tissues, knockdown/knockout models) and include appropriate secondary-only/isotype controls for imaging workflows.

Additional product notes (from provided fields)

• Specificity: No cross reactivity with other proteins.
• Background: HLA class II histocompatibility antigen, DR alpha chain?is a?protein?that in humans is encoded by the HLA-DRA?gene. It is mapped to 6p21.32. HLA-DRA is one of the HLA class II alpha chain paralogues. This class II molecule is a heterodimer consisting of an alpha and a beta chain, both anchored in the membrane. It plays a central role in the immune system by presenting peptides derived from extracellular proteins. Class II molecules are expressed in antigen presenting cells (APC: B lymphocytes, dendritic cells, macrophages). The alpha chain is approximately 33-35 kDa and its gene contains 5 exons. Exon 1 encodes the leader peptide, exons 2 and 3 encode the two extracellular domains, and exon 4 encodes the transmembrane domain and the cytoplasmic tail. DRA does not have polymorphisms in the peptide binding part and acts as the sole alpha chain for DRB1, DRB3, DRB4 and DRB5.
• Cross reactivity: No cross-reactivity with other proteins.
• Cellular localization: Cytoplasm. Neuron projection.
• Research category: Signal Transduction

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.