Anti-Mouse EpCAM (CD326) [Clone G8.8] — Purified in vivo PLATINUM^TM Functional Grade

Clone G8.8 is commonly used in vivo in mice to identify, isolate, and study EpCAM (CD326)-positive epithelial and thymic epithelial cells, primarily via flow cytometry, cell sorting, and immunostaining methods.

Key in vivo applications include:

• Isolation and purification of EpCAM+ cell populations: G8.8 facilitates the separation and study of epithelial cells (including thymic epithelial cells) by flow cytometry or magnetic bead sorting in live mice.
• Identification of alveolar and progenitor cells: The antibody enables mapping and activity studies of stem and progenitor cells in the lung and other tissues in vivo.
• Humanized mouse studies: Used in the characterization of human thymic epithelial cells reconstituted in murine hosts, especially in modeling immune responses or autoimmune diseases such as SLE.
• CAR-T research: G8.8-derived scFv is used to generate chimeric antigen receptors (CARs) targeting mouse EpCAM in adoptive cell transfer experiments, facilitating in vivo assessment of EpCAM-targeting therapies, including toxicity and biodistribution studies.
• Functional and mechanistic studies: Used to investigate the role of EpCAM in cell adhesion, organ morphology, and disease states (e.g., congenital tufting enteropathy, cancer).

Additional uses:

• Immunohistochemistry (IHC), Immunofluorescence (IF), Flow Cytometry (FC), Immunoprecipitation (IP), and Western Blotting (WB): G8.8 is validated for diverse in vivo and ex vivo applications for marking epithelial populations in tissues.
• Disease modeling: Applied in studies of epithelial cell biology, tissue regeneration, and immune-mediated pathologies where EpCAM-expressing cells are involved.

G8.8 is highly specific for mouse EpCAM and does not cross-react with human or rat EpCAM, ensuring clear interpretation in murine experimental settings.

Commonly Used Antibodies and Proteins with G8.8 in the Literature

G8.8 is a well-known rat monoclonal antibody specific for mouse EpCAM (CD326), commonly used to identify, isolate, and study epithelial cells and their subsets in mouse models. In research, G8.8 is frequently used in combination with several other antibodies and proteins to provide a more comprehensive characterization of cell populations. Below is a summary of the most commonly co-used markers and proteins:

Co-Stained Markers with G8.8

Typical Experimental Contexts

• Epithelial Cell Identification: G8.8 is often paired with cytokeratins (CK8, CK18), E-cadherin, or pan-cytokeratin to confirm the epithelial nature of cells, particularly in cancer research and cell sorting.
• Stem Cell and Cancer Stem Cell Profiling: CD44 and CD24 are frequently co-stained with G8.8 to identify and isolate subpopulations with stem-like or cancer stem cell properties.
• In Vivo Applications: G8.8 is used for in vivo depletion or tracking of EpCAM-positive cells, sometimes in combination with lineage or functional markers depending on the research question.

Summary Table

Key References

• Cytokeratins, E-cadherin, and pan-cytokeratin are highlighted as frequent partners for G8.8 in epithelial and tumor marker studies.
• CD44 and CD24 are explicitly mentioned as common co-stains with G8.8 for cell subset profiling.
• G8.8 itself is consistently described as a tool for mouse epithelial cell studies, especially in thymic biology and immunology.

In summary, the most commonly used antibodies and proteins alongside G8.8 are CD44, CD24, cytokeratins (CK8, CK18), E-cadherin, and pan-cytokeratin, primarily to profile, isolate, and functionally characterize epithelial and cancer cell populations in mouse models.

Clone G8.8 is a rat monoclonal antibody widely used in scientific research for the detection and isolation of mouse EpCAM (CD326)-positive cells, particularly in immunology and thymic biology studies.

Key findings from G8.8 citations include:

• Reliable cell sorting and identification: G8.8 has become the methodological standard for isolating EpCAM-expressing epithelial cells, especially in mouse models, due to its specificity and robust performance in flow cytometry and related applications.
• Specificity: G8.8 is unequivocally specific to mouse EpCAM, and does not cross-react with human or rat EpCAM.
• Applications: The antibody has been extensively used in:
  • Flow cytometry
  • Immunohistochemistry of frozen tissue sections (notably on acetone-fixed samples)
  • Immunofluorescence, immunoprecipitation, and Western blotting
  • Thymic epithelial cell purification and immune cell profiling, underpinning studies in thymic biology and T-cell development.
• Thymic biology and immune profiling: G8.8 is essential for research into mouse thymic epithelial cell populations, allowing researchers to dissect thymic structure, epithelial heterogeneity, and immune cell interactions within the thymus.
• EpCAM as a marker: Its use affirms EpCAM’s functional importance as a marker for epithelial cell adhesion, especially in the context of immune development and tissue organization.

Relevant citations across research indicate:

• Historical impact: Several foundational immunology studies on thymic biology and epithelial cell heterogeneity reference G8.8, establishing it as a reference tool.
• Methodological reproducibility: Its performance is recognized as highly reproducible, making it suitable for both analytical and preparative protocols in mouse tissue research.

Limitations and usage notes:

• Species restriction: G8.8 is functionally limited to mouse studies and cannot be used for human or rat EpCAM detection.
• Protocol optimization: Laboratory users are advised to titrate antibody concentrations for their specific applications to achieve optimal results.

In summary, G8.8 is a benchmark monoclonal antibody for mouse EpCAM-based research, central to protocols in epithelial cell identification, immune profiling, and thymic biology.

Dosing Regimens of Clone G8.8 in Mouse Models

Overview of Clone G8.8Clone G8.8 is a rat monoclonal antibody (mAb) specific for mouse EpCAM (CD326), commonly used in research for epithelial cell studies, immune cell profiling, and particularly in thymic biology. Its applications span flow cytometry, immunohistochemistry, immunofluorescence, and more, but its use in in vivo experiments is less standardized.

Published Dosing Information

• No Standardized In Vivo Dosing: There is no well-defined, published standard dosing regimen for clone G8.8 across various mouse models in the literature. Dosing is typically determined empirically—researchers optimize the dose based on their experimental needs, endpoints, and the specific model being used.
• Lack of Model-Specific Guidance: Suppliers and research databases emphasize that dosing should be tailored to the experimental context, but they do not provide model-specific recommendations or comparative data across different strains or disease models.

General Considerations for Antibody Dosing in Mice

• Empirical Optimization: Because in vivo antibody kinetics, target expression, and model biology can vary widely, most monoclonal antibodies require empirical titration to find the optimal dose. This is especially true for research-grade reagents like G8.8, which are not typically developed for therapeutic use with established dosing protocols.
• Benchmarking with Other mAbs: While not directly applicable to G8.8, some published studies provide general benchmarks for antibody dosing in mice. For example, dosing regimens for antibody-drug conjugates in xenograft models often use frequent administration (e.g., 2.5 mg/kg every 4 days), but these are specific to therapeutic contexts and may not be relevant to research-grade reagents like G8.8.
• Application-Specific Titration: For in vitro assays such as flow cytometry, vendors provide starting recommendations (e.g., ≤1 µg per million cells), but these do not translate directly to in vivo dosing.

Why Is There No Universal Dosing?

• Diversity of Mouse Models: Different mouse models (e.g., wild-type, transgenic, tumor-bearing, immunodeficient) can exhibit variable target expression, pharmacokinetics, and immune responses.
• Differing Experimental Goals: Some studies may require acute depletion (e.g., for lineage tracing), while others may need sustained modulation (e.g., for chronic disease modeling).
• Lack of Clinical Development: G8.8 is primarily a research tool, not a therapeutic agent. Therapeutic antibodies often undergo rigorous dose-finding studies, but research antibodies rarely do.

Practical Recommendations

• Empirical Dose-Finding: Researchers should perform pilot experiments to determine the effective dose in their specific model and for their experimental readout.
• Literature Review: Consult prior publications using G8.8 in similar models as a starting point, though recognize that even here, doses may not be directly comparable.
• Vendor Consultation: Some suppliers may offer technical support or unpublished data from other researchers, but this is not guaranteed.
• Titration and Controls: Always include dose titration and appropriate controls to validate efficacy and specificity.

Summary Table

Conclusion

There is no standardized dosing regimen for clone G8.8 across different mouse models; dosing must be empirically determined for each experimental context. Researchers should consult existing literature, perform dose-finding experiments, and carefully titrate to achieve their desired biological effect. The lack of universal guidelines reflects the reagent's research-grade status and the inherent variability of mouse models in biomedical research.