In Vivo Star Anti-Human HLA-DR Antibody

Cat # Size Price Quantity
5179011 mg$160
5179025 mg$400
51790325 mg$1100

Product Details


CloneL243
ApplicationDirect ELISA, functional assay, Flow Cytometry
Host SpeciesCHO cells
ReactivityHuman
FormatLiquid
Target NameHLA-DR, Major Histocompatibility Class II, MHC class II
Product DescriptionIn vivo Grade Recombinant Anti-Human HLA-DR Monoclonal Antibody
IsotypeMouse IgG2a Kappa
Antibody TypeRecombinant
Regulatory StatusRUO
Purity>95% by reducing SDS-PAGE
Endotoxin< 1 EU per 1 mg of the protein by the LAL method.
Storage Conditions4ºC
GradeIn vivo
Recommended UsageThis product is suitable in in vitro functional assays or in vivo on human cells used in animal models. Optimal amounts need to be determined empirically for each experiment.
Research AreasAntigen presentation, Dendritic cells, B cells, monocytes, macrophages, Autoimmunity, Cancer Immunology
See All FormatsClone L243

Background Information


HLA-DR is a major histocompatibility complex (MHC) class II molecule that plays a central role in adaptive immune responses by presenting antigenic peptides to CD4⁺ T helper cells. It is primarily expressed on professional antigen-presenting cells (APCs), including dendritic cells, macrophages, B cells, and thymic epithelial cells, and its expression can be induced on other cell types under inflammatory conditions, particularly by interferon-γ.

Structurally, HLA-DR is a heterodimer composed of an α chain (DRA) and a β chain (DRB), each containing two extracellular domains, a transmembrane region, and a short cytoplasmic tail. The α1 and β1 domains together form the peptide-binding groove, which accommodates peptides typically 13–25 amino acids in length. This groove is open at both ends, allowing for flexibility in peptide size. HLA-DR is highly polymorphic, particularly in the DRB genes, enabling the immune system to present a broad repertoire of antigenic peptides derived from pathogens or self-proteins. The ligands of HLA-DR are processed peptide antigens generated from extracellular or vesicular proteins that are internalized, degraded in endosomal compartments, and loaded onto HLA-DR molecules. Peptide loading is tightly regulated by accessory molecules, including the invariant chain (Ii), which prevents premature peptide binding, and HLA-DM, which facilitates peptide exchange and stabilizes high-affinity peptide–HLA-DR complexes. The primary functional interaction of HLA-DR is with the T cell receptor (TCR) on CD4⁺ T cells, initiating T cell activation and differentiation.

HLA-DR is strongly implicated in disease. Specific HLA-DR alleles are associated with susceptibility or protection in numerous autoimmune diseases, including rheumatoid arthritis, type 1 diabetes, systemic lupus erythematosus, and multiple sclerosis, reflecting differences in self-antigen presentation. Aberrant or reduced HLA-DR expression is also observed in cancer and sepsis, where impaired antigen presentation contributes to immune evasion or immunosuppression. Conversely, elevated HLA-DR expression on monocytes is often used as a marker of immune activation and immune competence.

Therapeutically, HLA-DR has both direct and indirect relevance. Anti-HLA-DR monoclonal antibodies have been explored in transplantation and hematologic malignancies to modulate immune responses or deplete malignant APCs. In cancer immunotherapy and vaccine development, effective antigen presentation via HLA-DR is essential for robust CD4⁺ T cell help, supporting durable antitumor and antiviral immunity. Additionally, HLA-DR expression is widely used as a diagnostic and prognostic biomarker in immunology, oncology, and critical care settings.

Data Sheets


In Vivo Star Anti-Human HLA-DR Antibody TDS

Related Protocols


Direct ELISA Protocol

Flow Cytometry Protocol

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Frequently Asked Questions


What are In Vivo Star Biofunctional Antibodies?
In Vivo Star antibodies are premium-grade monoclonal antibodies purified and formulated specifically for use in animal studies. Each lot is manufactured under stringent quality controls to ensure the low endotoxin levels, high purity, and functional activity required for reliable in vivo results.

How are these antibodies different from standard research antibodies (e.g., for Western blot or flow cytometry)?
Standard research antibodies are optimized for in vitro detection assays and may contain preservatives, carrier proteins (like BSA), or higher endotoxin levels unsuitable for injection. In Vivo Star antibodies are formulated in injectable-grade, azide-free, low-endotoxin buffers and validated for functional bioactivity in living systems rather than just antigen binding.

What endotoxin and purity specifications do these antibodies meet?
All In Vivo Star antibodies are tested and certified to meet low-endotoxin thresholds (typically <1 EU/mg, lot-dependent) using the LAL (Limulus Amebocyte Lysate) assay, and are purified to ≥95% purity by SEC-HPLC or SDS-PAGE. Exact specifications are provided on the Certificate of Analysis (CoA) for each lot.

Are these antibodies azide-free and carrier-free?
All In Vivo Star antibodies are formulated without sodium azide and without carrier proteins such as BSA or gelatin, since both can interfere with animal physiology or immune readouts during in vivo studies.

Do you provide isotype controls?
Matched isotype control antibodies (same host species, isotype, and formulation) are available upon request for most clones to support proper experimental controls.

How should In Vivo Star antibodies be stored and handled?
Store at 4°C for short-term use and avoid repeated freeze-thaw cycles, which can reduce bioactivity; aliquoting is recommended for long-term storage per the product-specific storage instructions on the Certificate of Analysis. Always confirm storage conditions and expiration on the CoA that accompanies each lot, as these can vary slightly by antibody.

Have a product or application question? Consult our FAQs or contact us.