Anti-Mouse CD32/CD16 [Clone 2.4G2] — Purified in vivo PLATINUM™ Functional Grade

Clone 2.4G2 is an anti-mouse CD16/CD32 antibody widely used in vivo to block Fc gamma receptors (Fc?Rs), primarily CD16 (Fc?RIII) and CD32 (Fc?RII), on murine leukocytes. This prevents non-specific binding of experimental antibodies to these receptors, minimizing background signal and improving the specificity of downstream biological or immunological assays.

Key context and usage:

• Blocking Fc? Receptors: By binding to CD16 and CD32 on B cells, monocytes, macrophages, NK cells, neutrophils, granulocytes, mast cells, and dendritic cells, clone 2.4G2 blocks the interaction between endogenous IgG and these Fc receptors. This is especially relevant in immunological studies where experimental antibodies might otherwise interact non-specifically via Fc?Rs, resulting in confounding effects.
• Formulation for In Vivo Use: Clinical-grade formulations used in vivo are specifically prepared without azide and with low endotoxin, in buffered saline, as required for administration to mice to avoid toxicity or immune artifacts. The documentation for in vivo use emphasizes these formulation criteria.
• Typical Protocol: In in vivo studies, 2.4G2 is commonly administered by intravenous or intraperitoneal injection before introducing other antibodies or performing immune manipulations, ensuring that Fc?R-expressing cells are blocked systemically.

Applications in in vivo mouse studies include:

• Fc receptor blocking prior to therapeutic antibody administration, to clarify the role of Fc? receptor interactions in antibody efficacy or safety.
• Prevention of non-specific immune activation caused by anti-mouse IgG treatments.
• Functional studies exploring the role of Fc? receptors in immune pathways, autoimmunity, or inflammation.

Key considerations:

• Selection of an appropriate formulation (often in vivo-grade, azide-free, low endotoxin) is required for animal use to avoid confounding toxicity or immune responses.
• The antibody prevents non-specific antibody-Fc?R interactions both in vivo and in ex vivo experiments such as flow cytometry or cell sorting by prior in vivo injection.

In summary, clone 2.4G2 is a critical tool for in vivo mouse studies to block Fc?Rs, enabling precise immunological analysis and reducing non-specific effects of antibody-based interventions.

When using 2.4G2 (anti-mouse CD16/CD32) for Fc receptor blocking in flow cytometry or immunofluorescence, researchers commonly combine it with a variety of other antibodies to identify specific immune cell populations or detect cell surface markers.

Commonly used antibodies or proteins in such panels include:

• B220 (clone RA3-6B2): Identifies B cells.
• CD3e (clone 145-2C11): Marks T cells.
• CD11b (clone M1/70): Marks monocytes and macrophages.
• CD19 (clone 6D5): Another B cell marker.
• CD45 (clone 30-F11): Pan-leukocyte marker.
• CD49b (clone DX5): Identifies NK cells.
• CD62L (clone MEL-14): Differentiates naive vs. memory T cells.
• Gr1 (clone RB6-8C5): Marks granulocytes.
• Ly6G (clone 1A8): Neutrophil marker.
• NK1.1 (clone PK136): Another NK cell marker.
• TCR? (clone H57-597): T cell receptor marker.
• IgE (clone R35-72): Detects IgE-expressing cells.

In addition:

• Anti-IgG secondary antibodies may be required for detection, but note that anti-rat IgG2b should be avoided as a secondary when 2.4G2 is used for Fc blocking.
• Panels may include antibodies against human Fc? receptors (e.g., anti-huFc?RI/CD64, anti-huFc?RIIb/CD32B) for cross-species studies.

This combination enables precise identification of cell types and functional states while minimizing background from non-specific Fc-mediated antibody binding. The specific choice depends on the experimental goals and cell populations of interest.

The Clone 2.4G2 monoclonal antibody is widely used in scientific research, particularly for its specificity towards mouse CD16 and CD32, which are Fc? receptors. Here are some key findings and applications from the available literature:

1. Specificity and Reactivity:

   • The 2.4G2 antibody specifically reacts with mouse CD16 (Fc?RIII) and CD32 (Fc?RII) and has been reported to react non-specifically via its Fc domain to Fc?RI.
   • CD16 and CD32 are expressed on various immune cells, including B cells, monocytes/macrophages, NK cells, granulocytes, mast cells, and dendritic cells.

2. Applications in Flow Cytometry and Immunofluorescence:

   • The 2.4G2 antibody is commonly used in flow cytometry and immunofluorescence staining experiments to block Fc receptors, preventing non-specific binding of the Fc portion of IgG to these receptors before staining with antigen-specific primary antibodies.

3. Fc Blocking and In Vivo Use:

   • The antibody and its Fab fragments have also been used to block Fc receptors in vivo, which is crucial for experiments requiring reduced non-specific binding.
   • When used for Fc blocking in immunoassays, the secondary antibody should not be anti-rat IgG2b to avoid cross-reactivity.

4. Immunological Studies:

   • While the search results do not provide specific citations from studies using Clone 2.4G2, its widespread use in immunology is evident. It is often used to study immune cell interactions and to control non-specific binding in various immunological assays.

For detailed application-specific information, it is recommended to consult specific scientific studies or product datasheets, as the optimal working conditions and applications can vary based on the experimental setup.

Dosing regimens for clone 2.4G2 (anti-mouse Fc?RII/III) typically involve a single intraperitoneal injection of 500?µg per mouse, but regimen details can vary based on the mouse model, experimental objective, and disease context.

Key regimen details and variability:

• Most published studies, using C57BL/6 or BALB/c mice, administer 500?µg of 2.4G2 intraperitoneally, often as a single dose 24 hours before the experimental intervention (such as antigen challenge, antibody administration, or tumor inoculation).
• In experiments studying dendritic cell function (OVA epicutaneous immunization in C57BL/6 mice), the 500?µg dose is given 24 hours prior to antigen application, with cellular outcomes assessed 6–48 hours later.
• There is limited published evidence for dose-ranging studies or alternative schedules (e.g., repeated dosing or varying amounts) for 2.4G2 in the literature, as the single-dose, 500?µg regimen is widely adopted due to its effective blockade of Fc?RII/III.
• Some studies may adjust timing or repeat dosing if prolonged Fc receptor blockade is needed, but empirical support for such variations is often not detailed in primary literature. The vast majority employ the "single 500?µg IP injection" approach.

Contextual notes:

• Mouse strain or disease model (e.g., infection, immunization, tumor) generally does not alter the standard 2.4G2 dose, but the timing relative to challenge may differ per experimental protocol.
• 2.4G2 targets both Fc?RII (inhibitory) and Fc?RIII (activating), so effects may differ between naïve and sensitized or diseased animals; this is considered in experimental interpretation, not dosing per se.

Summary Table: 2.4G2 Common Dosing Regimens

In summary: The dosing regimen of clone 2.4G2 is largely standardized across mouse models, typically employing a single 500?µg intraperitoneal injection 24 hours prior to the experimental intervention; major protocol variations are rare and not routinely reported in the literature.