Anti-Rat Kappa Light Chain (Clone MAR 18.5) – Purified in vivo GOLD™ Functional Grade

The most common in vivo application of clone MAR 18.5 in mice is as an anti-rat kappa light chain monoclonal antibody used to target and deplete cells or antibodies of rat origin that have been administered to mice.

Key uses include:

• Depletion protocols: MAR 18.5 is routinely employed to deplete rat monoclonal antibodies or rat-derived cells introduced into mice, particularly in experiments where rat antibodies are used for cell targeting (such as B cell depletion).
• Combination B cell depletion: It is often used in combination with anti-CD19 and anti-CD22 antibodies to enhance in vivo B cell depletion. MAR 18.5 can bind to the rat kappa chains present on these antibodies, facilitating their removal and thereby depleting B cells more effectively.
• Secondary cross-linking agent: MAR 18.5 has been used as a secondary antibody to cross-link rat-derived primary antibodies in functional studies, such as for inducing Fc gamma receptor-mediated phagocytosis in mouse macrophages.
• Support for immunotherapy research: In protocols involving the administration of rat mAbs into mice, such as immune cell depletion or immune cell tracking, MAR 18.5 is used to modulate or terminate the activity of the administered antibodies, preventing off-target effects and enabling clearer interpretation of experimental outcomes.

Summary of typical in vivo applications:

• Antibody depletion of rat-origin mAbs in mice
• In vivo B cell depletion when rat anti-mouse CD19/CD22 mAbs are used
• Functional studies requiring secondary antibody cross-linking

MAR 18.5 is not used to target mouse endogenous cells but instead to manipulate or clear rat immunoglobulins or rat-derived hybridoma cells introduced into the mouse model.

These applications are foundational in immunology experiments where rat antibodies are essential reagents but ongoing rat antibody activity would confound results if not specifically depleted.

In the literature, the MAR 18.5 antibody, which targets the rat kappa light chain, is commonly used in conjunction with several other antibodies and proteins for various applications. Some of these include:

• Anti-CD19 and Anti-CD22: These are frequently used together with MAR 18.5 for in vivo B cell depletion studies in rats or mice. Anti-CD19 and Anti-CD22 target different markers on B cells, enhancing the specificity and efficacy of B cell depletion when used in combination with MAR 18.5.

• J11d.2 (anti-heat-stable Ag), 2.43 (anti-CD8), M5/114 (anti-class II), and 2.4G2 (anti-FcR): These are used in combination with MAR 18.5 for T cell isolation and complement lysis, offering a comprehensive approach to studying immune cell populations.

These combinations are prevalent in research involving immunology, particularly in studies focused on immune cell depletion and isolation.

Clone MAR 18.5 is a monoclonal antibody most commonly cited for its specific binding to the rat kappa immunoglobulin light chain and is frequently used as a tool in rodent immunology for both analytical and functional purposes.

Key findings from its scientific citations include:

• Antigen specificity: MAR 18.5 binds specifically to the kappa light chain of rat immunoglobulins, recognizing both RI-1a and RI-1b allotypes.
• Production background: It was developed by immunizing SJL/J mice with soluble rat immunoglobulin and creating a hybridoma that produces the MAR 18.5 IgG2a kappa monoclonal antibody.
• Applications:
  • Widely used for B cell depletion in vivo (often in combination with other antibodies such as anti-CD19 and anti-CD22) in mouse models.
  • Used as a secondary antibody or for cross-linking in experimental setups investigating Fc gamma receptor-mediated functions, such as in macrophage activation studies.
  • Facilitates T cell isolation and complement lysis protocols, often in panels with other lineage-specific antibodies.
  • Utilized in immunoassays like ELISA, flow cytometry (FC), immunoprecipitation (IP), immunohistochemistry (IHC), Western blot (WB), and cell depletion experiments.
• Role in neutrophil studies: In neutrophil depletion protocols in mice, MAR 18.5 is used as a part of multi-antibody strategies, sometimes revealing challenges with antigen masking which can be addressed using intracellular detection techniques.

Further, MAR 18.5 is noted for its strong binding to protein A, which simplifies its purification and downstream uses in biochemical assays.

Overall, MAR 18.5 is highly cited in immunological research for its reliability in depleting and tracking kappa-positive B cells, as well as for its utility in various experimental protocols involving the rat kappa chain.

Dosing Regimens of Clone MAR 18.5 Across Different Mouse Models

Introduction:Clone MAR 18.5 is a monoclonal antibody directed against rat kappa light chains, commonly used in mouse models for B cell depletion studies and other immunological applications. However, dosing regimens for this antibody are not fully standardized across different mouse models, varying based on experimental application and mouse strain.

Variability in Dosing Regimens:

1. Lack of Standardization:

   • There is no universally agreed-upon dosing regimen for MAR 18.5 across all mouse models. Dosing can vary significantly based on specific research objectives and the particular mouse strain used.

2. General Dosing Range:

   • One commonly cited dosing regimen for MAR 18.5 involves administering 50 µg per mouse, typically via intraperitoneal injection. However, this is not universally applied and can be adjusted based on the specific requirements of the study.

3. Applications in B Cell Depletion:

   • When used in combination with anti-CD19 and anti-CD22 for in vivo B cell depletion, the dosing might be adjusted to ensure effective depletion while minimizing side effects. This combination is often used in studies assessing B cell roles in autoimmunity, infection, or cancer models.

4. Experimental Flexibility:

   • Researchers may need to conduct preliminary studies to determine the optimal dose for their specific experimental setup, as different models (e.g., autoimmune disease, infection, or cancer) may require different dosing strategies.

Conclusion:

In summary, while there is a general guideline of 50 µg per mouse for MAR 18.5, the dosing regimen can vary significantly based on the specific mouse model and experimental objective. Researchers should consult existing literature and potentially conduct preliminary dose-finding studies to optimize dosing for their particular application.