pbs-4 Antibody
Description
Definition and Context
Antibodies labeled with "PBS-4" typically denote formulations in PBS buffer without stabilizers like BSA or azides, optimized for downstream conjugation. For example:
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Glypican 4 Antibody (83749-4-PBS): A recombinant rabbit monoclonal antibody targeting glypican 4 (GPC4), a heparan sulfate proteoglycan involved in cell growth regulation .
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Storage: PBS-only buffer (1 mg/mL), enabling direct use in ELISAs, cytometric bead arrays, or multiplex assays .
Glypican 4 Antibody (83749-4-PBS)
| Parameter | Details |
|---|---|
| Host/Isotype | Rabbit IgG |
| Reactivity | Human |
| Applications | Cytometric bead array, Indirect ELISA |
| Conjugate | Unconjugated (ready for custom conjugation) |
| Immunogen | Glypican 4 fusion protein (Ag3670) |
| Molecular Weight | 62 kDa (556 amino acids) |
| Storage | -80°C in PBS-only buffer (BSA/azide-free) |
| Clone | 240806D12 |
Research Applications
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Matched Antibody Pairs: Used with detection antibody 83749-3-PBS for multiplex assays (e.g., Cytometric bead array) .
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Functional Advantages: Recombinant production ensures batch-to-batch consistency and scalability .
Related Antibodies in PBS Formulations
While not explicitly named "PBS-4," other PBS-formulated antibodies include:
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Thrombospondin-4 Antibody (MAB2390): Targets thrombospondin-4 (THSP4), a calcium-binding protein involved in extracellular matrix interactions .
Mechanistic Insights from Analogous Antibodies
Studies on PBS-compatible antibodies highlight broader functional principles:
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Pathogenicity: Anti-PF4 (platelet factor 4) antibodies in PBS formulations can induce thrombotic disorders (e.g., heparin-induced thrombocytopenia) by clustering PF4 tetramers, triggering platelet activation .
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Autoimmune Effects: High-avidity anti-AQP4 antibodies (e.g., in neuromyelitis optica) penetrate the CNS via circumventricular organs, causing astrocyte damage .
Clinical and Preclinical Implications
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Cancer Immunotherapy: Bispecific antibodies (e.g., anti-4-1BB×PDL1) in PBS-based buffers enhance CD8+ T-cell responses and synergize with anti-PD1 therapies .
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Muscle Disorders: Anti-LTBP4 antibodies improve muscle function in dystrophy models by reducing TGFβ signaling .
Validation and Quality Control
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Assay Compatibility: PBS-formulated antibodies are validated in ELISA, Western blot, and functional assays (e.g., HIPA test for platelet activation) .
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Cross-Reactivity: Antibodies like THSP4 show species-specific reactivity (e.g., 50% cross-reactivity with mouse THSP4) .
Limitations and Considerations
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Storage Stability: PBS-only formulations require ultra-low temperatures (-80°C) to prevent aggregation .
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Titration Needs: Optimization is required for each application due to variable binding kinetics .
Future Directions
Product Specs
Constituents: 50% Glycerol, 0.01M Phosphate Buffered Saline (PBS), pH 7.4
Target Background
Q&A
Basic Research Questions
How to validate PBS-4 antibody specificity for immunohistochemistry (IHC)?
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Methodological approach:
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Perform epitope mapping using truncated antigen variants or competitive binding assays with known ligands .
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Validate via Western blotting under reducing/non-reducing conditions to confirm target band specificity .
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Use knockout cell/animal models as negative controls to verify absence of non-specific binding .
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What optimization steps are critical for PBS-4 antibody dilution in flow cytometry?
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Key protocols:
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Conduct titration assays across a dilution range (e.g., 1:50 to 1:800) using positive/negative control cells .
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Optimize permeabilization with 0.01% saponin to maintain epitope accessibility while minimizing background .
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Validate using compensation beads for spectral overlap correction in multispectral panels .
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How to address non-specific binding in PBS-4 antibody applications?
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Solutions:
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Use pre-adsorbed secondary antibodies to minimize cross-reactivity with endogenous immunoglobulins .
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Implement blocking buffers containing 5% species-matched serum or 1% BSA/0.01% saponin for intracellular targets .
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Include isotype controls at matched protein concentrations to distinguish background signal .
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Advanced Research Questions
How to resolve contradictory PBS-4 expression data across experimental models?
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Analytical framework:
How to design a multispectral panel including PBS-4 for mass cytometry?
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Design principles:
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Pair PBS-4 (lanthanide-labeled) with markers of distinct abundance (e.g., high-abundance CD45, low-abundance cytokines) .
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Use metal isotope tags with minimal signal overlap (e.g., ¹⁶⁴Dy for PBS-4, ¹⁶⁰Gd for secondary markers) .
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Validate panel using reference cell lines with known PBS-4 expression levels .
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What strategies confirm PBS-4’s role in observed signaling pathways?
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Functional validation:
Methodological Best Practices
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Antibody validation: Require ≥3 independent validation methods (e.g., IHC, flow cytometry, knockout validation) from peer-reviewed studies .
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Data reproducibility: Archive aliquots at -80°C with 1% BSA/0.01% sodium azide to prevent freeze-thaw degradation .
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Conflict resolution: For discrepant results, re-analyze raw data using unmixing algorithms (e.g., FlowJo’s spectral unmixing) and confirm with orthogonal methods (e.g., microscopy) .
