Rat IgG₁ Isotype Control [Clone GL113] — Purified in vivo PLATINUM™ Functional Grade

Clone GL113 is a rat IgG1 monoclonal antibody most commonly used as an in vivo isotype control in mouse studies. Its primary applications involve serving as a negative control to distinguish the specific effects of experimental antibodies from non-specific background effects caused by the antibody’s Fc region or other non-antigen-specific interactions.

Key in vivo applications in mice include:

• Use as an isotype control: GL113 is administered to mice in parallel with a test antibody to determine background or non-specific effects in immunological experiments, particularly those involving antibody therapies, cell depletion, or immune modulation.
• Ensuring validity of experimental results: By comparing outcomes between GL113-treated and experimental antibody-treated animals, researchers can accurately attribute observed effects to the specific targeting of the experimental antibody rather than generic rat IgG1-mediated effects.
• Controls in disease models: GL113 is used as a control in a variety of disease models, including cancer, infection, or autoimmune disease, wherever in vivo antibody administration is required.

While GL113's original target is beta-galactosidase, its lack of reactivity in the mouse immune system allows it to function as an ideal isotype control without interfering with most biological processes in vivo. It is not typically used as a functional (neutralizing or depleting) reagent, but solely for control purposes. Some specialized uses may involve testing with encapsulated cells or immunization models to measure non-specific antibody effects, but these are secondary to its main role.

GL113 is not to be confused with functional anti-mouse IL-4 antibodies (e.g., clone 11B11), which are used for cytokine neutralization; GL113 specifically serves to control for non-antigen-specific effects in these and similar experiments.

While the search results do not provide specific details on other commonly used antibodies or proteins used with GL113 in the literature, they do mention several applications and related antibodies:

1. Anti-IL-13 antibodies: These are often used alongside GL113 or other isotype controls to block Th2-type responses, as IL-4 and IL-13 share receptor complexes and have overlapping biological functions.

2. GLP-1 R antibodies: These are involved in metabolic studies and have been developed for structural and functional applications, though not specifically mentioned in combination with GL113.

3. GPCR-targeting antibodies: These are a broader category of antibodies that target G protein-coupled receptors, which are prominent drug targets. They are not specifically linked to GL113 but represent a field of research similar in scope to using isotype controls like GL113.

Since GL113 is primarily used as a negative control in in vivo mouse studies, other antibodies or proteins used in conjunction with it would typically be those under investigation for their specific biological effects, often in the context of immunological or metabolic studies.

For more specific information on proteins or antibodies used alongside GL113, reviewing studies that employ this isotype control might provide additional insights.

Clone GL113 is repeatedly cited in scientific literature as a rat IgG1 isotype control antibody. Its principal role is to serve as a negative control in in vivo and in vitro experiments where specific antibody effects need to be distinguished from non-specific background responses.

Key findings from cited literature using GL113:

• Isotype Control Function: GL113 is not used to target antigens directly (except beta-galactosidase in some contexts), but rather to control for non-specific effects of rat IgG1 antibodies in experimental systems. This makes data interpretations regarding specificity more robust.

• Applications in Immunological Experiments:

  • It has been employed as a control in experiments involving antibody-mediated cell depletion, immunomodulation, and functional assays in mouse models.
  • For example, in cancer immunology studies, GL113 provided the negative control to confirm that observed effects following administration of active antibodies were specifically due to those antibodies and not background immune activation from the isotype.
  • In studies of autoimmune disease models (e.g., inflammatory arthritis), GL113 was used to control for effects of depleting CD25 or CTLA-4 in mice.
  • The antibody has been specifically used as the control in SARS-CoV-2 receptor research with mouse models, further illustrating broad relevance across biomedical research fields.

• Experimental Dosage and Protocols:

  • Literature commonly reports the use of GL113 at standardized dosages (e.g., 5 μg/ml for in vitro or 500 μg per animal for in vivo), ensuring comparability between studies.

• Validation of Specificity:

  • Use of GL113 confirms that observed functional effects in animal or cell studies (e.g., immune cell depletion, cytokine responses) can be attributed to the specific activity of test antibodies, and not to the general presence of rat IgG1.

• No Direct Biological Effect:

  • As an isotype control, GL113 is established to lack specific biological activity beyond the immunoglobulin isotype background, permitting discrimination between specific and nonspecific antibody-mediated effects in published studies.

In summary, scientific citations show that clone GL113 is a well-validated rat IgG1 isotype control essential for rigorous immunology, oncology, and infectious disease research, allowing researchers to attribute experimental outcomes to active antibodies rather than isotype background.

Dosing regimens of clone GL113 in mouse models vary primarily based on experimental objectives, but the most commonly reported protocol uses 1 mg per mouse administered intraperitoneally every five days for a total of six doses in typical tumor immunotherapy studies.

Additional published regimens show variability in dose and schedule:

• Dose Range: Studies report doses ranging from 100–500 µg per mouse, depending on the stringency of isotype controls or study-specific immunomodulation.
• Schedule: Administration frequency ranges from every two to five days, with more frequent dosing (2–3 times per week) utilized in studies requiring tighter immunomodulatory control.
• Route: The intraperitoneal route is the most common for GL113 administration in mouse models, due to ease and reproducibility.

Key factors influencing particular dosing choices:

• Study objective (e.g., tumor immunotherapy vs. general immunomodulation).
• Model strain and age (e.g., immunocompetent vs. immunodeficient mice).
• Expected antibody clearance and half-life.

For example, studies using GL113 as an isotype control in immunotherapy experiments often apply the higher end of the dosing range (1 mg every five days). In contrast, immunology studies exploring tolerance mechanisms may opt for lower, more frequent doses (100–500 μg every 2–4 days).

Published use case: In oral tolerance experiments, mice were injected with GL113 to assess its role as a control antibody; while the specific dose is not always reported, methodology is consistent with standard isotype control regimens.

Summary Table: Common GL113 Dosing Regimens in Mouse Models

If your experimental design requires deviation from these standards (e.g., different disease models or antibody pharmacokinetics), adjust dose and frequency based on published controls or pilot dose-finding studies. Always refer to the specific protocol for your mouse strain and disease model to ensure appropriate use.