Anti-Mouse F4/80 [Clone Cl:A3-1] — Purified in vivo GOLD™ Functional Grade

In in vivo mouse studies, clone Cl:A3-1 is primarily used as a monoclonal antibody that specifically detects the F4/80 antigen on tissue macrophages, enabling researchers to label, identify, and track macrophage populations within mouse tissues.

• Imaging and Biodistribution: Cl:A3-1 can be radiolabeled (e.g., with Indium-111) and injected into mice. It then binds specifically to F4/80+ macrophages, which allows for the imaging and quantification of macrophage infiltration in tissues and tumors using modalities such as SPECT/CT. In these studies, the antibody accumulates strongly in macrophage-rich organs (spleen, liver) and tumor sites, reflecting macrophage density and distribution in vivo.

• Functional Modulation: Administration of Cl:A3-1 in vivo has been shown to modulate cytokine release during immune responses (e.g., in the context of Listeria monocytogenes infection), allowing assessment of macrophage function and their role in immune regulation.

• Macrophage Depletion Studies: Cl:A3-1 can be used in conjunction with treatments such as liposomal clodronate to study the effects of macrophage depletion on tissue and immune function. Reduced uptake of labeled Cl:A3-1 after clodronate treatment confirms macrophage depletion and helps quantify changes in macrophage populations.

• Cellular Identification: In tissues, Cl:A3-1 selectively labels mature resident macrophages (including Kupffer cells, microglia, Langerhans cells, and others), enabling immunostaining-based identification and quantification in situ.

• Experimental Controls: Human anti-idiotypic antibodies against Cl:A3-1 are sometimes used as controls to block its activity, clarifying its functional effects in vivo.

In summary, clone Cl:A3-1 is a critical experimental tool for tracking, imaging, and functionally interrogating macrophages in living mice, supporting studies of immune function, inflammation, cancer, and tissue homeostasis.

Commonly used antibodies or proteins alongside Cl:A3-1 (anti-mouse F4/80) include those that mark other immune cell types or provide additional cell-type specificity or context within tissues. The literature frequently employs these combinations for identification, phenotyping, and functional studies of macrophages in murine models.

Key antibodies and proteins used with Cl:A3-1 include:

• CD11b (Mac-1): A pan-myeloid marker often used with F4/80 to distinguish monocyte and macrophage subpopulations.
• CD68: Another macrophage-associated marker useful in co-staining protocols to verify macrophage identity or discriminate between tissue-resident and infiltrating populations.
• CD45: A pan-leukocyte marker to confirm hematopoietic lineage and distinguish leukocytes from non-hematopoietic cells.
• CD79b: Used in some immunofluorescence protocols to distinguish B cells (e.g., green fluorescence), particularly in lymphoid tissue studies, where F4/80 (red) and CD79b (green) provide spatial context.
• DAPI: A nuclear counterstain (blue) frequently used alongside antibody cocktails in immunofluorescence/immunohistochemistry for identifying and quantifying total cell nuclei, providing context to specific cell marker staining.

These combinations are applied in research areas such as:

• CNS and microglia identification (e.g., with Iba1 for microglial specificity)
• Tumor-associated macrophage (TAM) studies (common use with CD11b, CD68, and sometimes Ly6C or CD206/MRC1 for macrophage subtype delineation)
• Tissue macrophage profiling in organs like liver (with Ly6G to exclude neutrophils) and spleen

In summary, Cl:A3-1 is commonly used with antibodies against CD11b, CD68, CD45, CD79b, and nuclear stains like DAPI in both flow cytometry and tissue staining protocols to precisely identify, differentiate, and characterize mouse macrophages and related cell types in a variety of experimental settings.

The scientific literature consistently cites clone Cl:A3-1 as a highly specific rat monoclonal antibody used to identify murine F4/80 antigen, a key marker for mouse macrophages and microglia. Its main findings and applications include:

• Gold standard macrophage marker: Cl:A3-1 is widely recognized as one of the most reliable antibodies to detect F4/80, a 160 kDa cell surface glycoprotein of the EGF-TM7 family, making it an essential tool in research on mouse innate immunity, inflammation, and tissue macrophage distribution.
• Specificity and versatility: The antibody shows high specificity for mouse F4/80/EMR1 and has been validated for use in a range of techniques, such as immunohistochemistry (IHC, including frozen and paraffin-embedded tissue), FACS, immunocytochemistry, immunoprecipitation, Western blot, and radioimmunoassay. It reacts strongly with thioglycollate-stimulated peritoneal macrophages from C57BL/6 mice.
• Functional relevance: Studies demonstrate that using clone Cl:A3-1 can modulate cytokine levels released in response to pathogens (e.g., Listeria monocytogenes), linking its use to functional immunological assays and cytokine profiling.
• Histological controls and blocking: Anti-idiotypic antibodies (e.g., AbD17867) have been developed specifically to bind and block Cl:A3-1, serving as key controls in histological studies using this clone, ensuring assay specificity.

Additional insights:

• In disease models such as chronic graft-versus-host disease (cGVHD), Cl:A3-1 is used to assess macrophage infiltration (via F4/80+ cells), contributing to the understanding of inflammatory pathogenesis in tissues like skin and lung. In these studies, the presence (or inhibition) of F4/80+ CX3CR1+ macrophages after therapeutic interventions reflects macrophage involvement in disease progression and treatment efficacy.

In summary, clone Cl:A3-1 is a cornerstone reagent for murine macrophage detection and quantification, central to immunology, tissue histology, and inflammation research.

Dosing regimens for clone Cl:A3-1—an antibody targeting mouse F4/80 as a macrophage and microglial marker—are not standardized across mouse models, and published sources do not report detailed or comparative dose schedules for Cl:A3-1 in vivo. Most available data confirm its application for immunohistochemistry and flow cytometry, with general statements indicating use as a macrophage marker, but do not specify dosing variations by mouse strain, disease model, or experimental context.

Essential context and supporting details:

• Clone Cl:A3-1 recognizes the murine F4/80 antigen (EMR1), a marker for mouse macrophages.
• Its generation involved immunizing rats with thioglycolate-elicited peritoneal macrophages from C57BL/6 mice, but this does not inform dosing regimen—it simply describes the origin of the clone.
• Application notes list various assays (e.g., electron microscopy, FACS, immunohistochemistry in frozen or paraffin-embedded tissue), yet do not include specific dosing quantities or schedules for in vivo studies.

Additional relevant information:

• For other antibodies in mouse models (e.g., anti-PD-1, anti-CTLA-4), typical in vivo doses are in the range of 100–500 µg per mouse, given by intraperitoneal injection every 3–4 days, but these are not specific to Cl:A3-1 and may not translate accurately.
• If Cl:A3-1 is intended for functional in vivo depletion or labeling, consulting published research using this clone, manufacturer recommendations, or dose-response pilot studies in the target model (strain, age, disease context) is essential.

In summary, published sources do not provide direct or comparative dosing regimens for Cl:A3-1 across mouse models. Researchers should refer to experimental literature or antibody manufacturer protocols for model-specific optimization.