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

Clone GL113 is a rat IgG1 isotype control antibody used in in vivo mouse studies primarily as a negative control to distinguish specific effects of an experimental antibody from nonspecific background signals. It is not directed against any mouse antigen relevant to the study, which ensures that any observed effects can be attributed to the test antibody rather than nonspecific binding or immune activation.

Key details for its use in in vivo mouse studies:

• Purpose: GL113 is administered to mice as a control antibody in experiments involving therapeutic or functional antibodies. This establishes a baseline for background responses, enabling researchers to accurately interpret the biological effects of a targeted antibody versus nonspecific IgG1 interactions.

• Administration & Dosing: In published studies, GL113 has been used at equivalent doses and schedules as the test antibody. For example, in a tumor immunotherapy study, mice received 1?mg of GL113 intraperitoneally every five days for a total of six doses, paralleling the dosing schedule of the experimental anti-IL4 antibody. The isotype control should always be used at the same concentration and by the same route as the primary antibody in the experiment.

• Product Attributes: GL113 is typically low endotoxin with high purity, making it suitable and safe for in vivo work and minimizing the risk of immune reactions to contaminants rather than the antibody itself.

• Assay Types: In addition to in vivo administration, GL113 may be used for flow cytometry (FC), immunohistochemistry (IHC), and immunofluorescence (IF) as a negative control, but its main application in mouse studies is as an in vivo control.

• Specificity: GL113 is specific as an anti-beta-galactosidase antibody (an irrelevant antigen in most mammalian studies), which further ensures minimal cross-reactivity with endogenous mouse proteins.

• Control Design: By comparing outcomes between animals given the active antibody versus GL113, researchers measure treatment-specific effects versus background or placebo effects.

GL113 is thus a standard rat IgG1 isotype control given to mice in preclinical studies to ensure the validity and specificity of experimental antibody-based interventions.

GL113 is an anti-mouse IL-4 monoclonal antibody commonly used for in vivo and in vitro neutralization of interleukin-4 (IL-4) in immunological experiments. In the literature, the use of GL113 is often part of multi-antibody or multi-protein strategies to dissect immune pathways, sometimes in combination with other cytokine-neutralizing antibodies, immune checkpoint inhibitors, or lineage/type-specific markers.

Commonly used antibodies or proteins alongside GL113 include:

• Anti-IL-13 antibodies: Because IL-4 and IL-13 share some receptor complexes and have overlapping biological functions, researchers often block both cytokines simultaneously to fully inhibit Th2-type responses.
• Anti-IL-5 antibodies: Used for broader blockade of Th2 cytokines.
• Isotype control antibodies: To validate the specificity of the effects observed with GL113.
• Anti-CD3 and anti-CD28 antibodies: Frequently used in T cell activation experiments and sometimes combined with cytokine blockade.
• Other cytokine-neutralizing antibodies: For instance, anti-IFN-? (to neutralize Th1 responses), anti-TNF?, or anti-IL-17A depending on experimental focus.
• Fluorescently labeled lineage markers (e.g., anti-CD4, anti-CD8, anti-B220/CD45R): In flow cytometry studies where GL113 is used to characterize effects on immune subsets.

In cancer immunology or transplantation models, checkpoint inhibitors (e.g., anti-PD-1, anti-CTLA-4) or tumor-targeted antibodies may also be used in conjunction with GL113 to assess combined effects on immune regulation. Additionally, protein G agarose is frequently used as part of the purification process for GL113 itself.

Researchers may pair GL113 with functional assays involving cytokine detection proteins (e.g., ELISA capture/detection antibodies for IL-4, IL-13, IFN-?).

GL113 usage tends to be method- and model-specific, so the exact combination partners are dictated by the hypothesis being tested (e.g., blockade of Th2 immunity versus modulation of allergic inflammation or tumor immunity).

Clone GL113 is widely referenced in scientific literature as a rat IgG1 isotype control antibody, primarily used to provide a negative control in experiments involving antibody-mediated detection or functional assays. It does not target mammalian antigens and is specific for E. coli ?-galactosidase, ensuring minimal cross-reactivity with mammalian samples.

Key findings and uses from GL113 citations include:

• Isotype Control Function: GL113 is routinely used as a control to rule out nonspecific immune responses in antibody-based experiments. For example, in immunological studies such as cytokine blockade or cell subset analysis, it serves to confirm that observed effects are due to specific binding or activity of the experimental antibody, and not the antibody itself or Fc-mediated effects.

• Application Context: Publications such as [PMC2840337] detail the use of GL113 to match the quantity and IgG1 subclass of experimental antibodies (e.g., anti-IL-10R1), validating experimental specificity. It was administered in vivo in mouse models without eliciting biological activity due to lack of relevant antigen binding.

• Quality Assurance: Suppliers and technical literature emphasize its use in flow cytometry, immunohistochemistry, and in vivo functional studies to minimize background and enhance data interpretation, particularly in hematologic, immunologic, and cancer research.

• Recent Citation Example: A 2024 study by Tzetzo et al., referenced in supplier citations, used GL113 as a negative control in research investigating immune cell regulation and cytokine response, further confirming its utility in immunological assays.

GL113 is not a discovery antibody and has no findings related to specific disease or pathway modulation—its significance in citations is as a gold-standard negative control for verifying experimental specificity and excluding off-target or subclass effects.

No scientific findings attribute biological activity, therapeutic potential, or disease relevance directly to GL113; its value is strictly methodological. This is reflected across cited literature, where GL113’s role is limited to controlling for variables in antibody-based studies.

Dosing regimens of clone GL113 (assuming this refers to an investigational antibody or conjugate similar in class to AMG 133 or related biologics) vary primarily according to the mouse strain/model, the intended pharmacodynamic effect, and the antibody’s pharmacokinetic properties. However, no direct data on GL113 itself is found in the provided search results: most referenced antibodies are for checkpoint blockade (e.g., anti-PD-1, anti-CTLA-4) or immune cell depletion, and AMG 133 (used in metabolic studies) is the only detailed antibody conjugate example.

Context from the Closest Available Data:

• For checkpoint blockade antibodies (e.g., anti-PD-1, anti-PD-L1, anti-CTLA-4):

  • Doses typically range from 100–500 µg per mouse.
  • Administration is most commonly intraperitoneal every 2–4 days.
  • Frequent dosing (2–3 times per week) is used in syngeneic tumor models (such as MC38, B16 melanoma).

• For conjugated antibodies similar to AMG 133 (antibody-peptide conjugates for metabolic studies):

  • In CD-1 mice, a single intravenous bolus dose of 5 mg/kg is used, with blood sampling over 14 days for PK analysis.
  • The regimen reflects the antibody’s long half-life (terminal ( t_{1/2} ) of ~118–206 h).

Model-Dependent Differences:

• Tumor models (e.g., MC38, B16):
  • Lower per-dose amounts (100–250 µg per mouse), frequent dosing (2–3 times weekly), usually intraperitoneal.
• Metabolic models/PK studies (CD-1, non-obese mice):
  • Higher single bolus dose (5 mg/kg), intravenous route, extended sampling period.

Influence of Experimental Aims and Antibody Format:

• The pharmacological target (checkpoint blockade vs. receptor antagonism) and antibody structure (Fc format, conjugate, isotype) dictate both dosing volume, interval, and route.
• Long-acting conjugates (as with AMG 133) are dosed less frequently at higher amounts to profile PK, whereas therapies aiming to modulate the immune response typically use repeated, lower doses for sustained effect.

Summary Table: Model vs. Dosing Example

If you require GL113-specific regimens, please provide model context or additional references, as the above regimens are inferred from similar antibody types and biologic conjugates in published mouse studies.