Antibodies like OR8H3 consist of two heavy chains and two light chains, forming a Y-shaped structure with variable regions that bind to specific epitopes. The specificity of antibodies ensures that OR8H3 antibodies exclusively recognize the OR8H3 receptor, avoiding cross-reactivity with other olfactory receptors . This specificity is achieved through somatic recombination of immunoglobulin genes, which generates a diverse repertoire of antigen-binding sites .
Key Structural Features:
Variable Regions: Determine antigen specificity via unique amino acid sequences.
Constant Regions: Mediate effector functions, such as complement activation or opsonization .
OR8H3 antibodies are primarily used in:
Olfactory Research: Studying the role of OR8H3 in scent perception and olfactory disorders.
Diagnostics: Detecting OR8H3 expression levels in tissues or bodily fluids to investigate its involvement in diseases .
Therapeutic Development: Potential use in targeting OR8H3-expressing cells for therapeutic interventions .
The OR8H3 ELISA Kit (ABIN1743686) is a widely used tool for quantitative analysis, offering a detection range of 50–1000 pg/mL with high sensitivity (1.0 pg/mL) .
Sample Handling: Factors like cell viability and sampling time impact assay accuracy .
Cross-Reactivity: Risk of binding to structurally similar receptors requires rigorous validation .
Immunological Tolerance: Autoreactive antibodies are typically eliminated, but disruptions may lead to autoimmune conditions .
OR8H3 is an olfactory receptor classified as a member of the large family of G-protein-coupled receptors (GPCRs). It plays a role in the detection of specific odors, initiating a neuronal response that triggers the perception of smell. The receptor protein is encoded by a single coding-exon gene and shares a 7-transmembrane domain structure with many neurotransmitter and hormone receptors . OR8H3 is primarily involved in odorant recognition and G protein-mediated transduction of odorant signals within the olfactory system.
Based on current research tools, OR8H3 antibodies have been validated for several applications:
| Application | Dilution Range | Validated Species |
|---|---|---|
| ELISA | 1:10000 | Human |
| Immunofluorescence (IF) | 1:200-1:1000 | Human |
| Western Blotting (WB) | 1:500-1:2000 | Human, Cow, Dog, Guinea Pig, Horse, Mouse, Pig, Rabbit, Rat |
These applications enable researchers to detect and analyze OR8H3 expression in various experimental contexts .
When selecting an OR8H3 antibody, researchers should consider:
Target specificity: Determine whether you need an antibody targeting a specific region (e.g., C-terminal) of OR8H3. For instance, ABIN7185373 targets the C-terminal region (AA 262-311) .
Host species and clonality: Most available OR8H3 antibodies are rabbit polyclonal antibodies .
Cross-reactivity profile: Some antibodies may cross-react with OR8H3 from multiple species, while others are human-specific .
Application compatibility: Verify that the antibody has been validated for your specific application (ELISA, IF, WB) .
Format requirements: Consider whether you need a conjugated or unconjugated antibody based on your detection system .
To maintain optimal activity of OR8H3 antibodies:
Store at -20°C or -80°C upon receipt.
Avoid repeated freeze-thaw cycles as this can degrade antibody quality.
For antibodies in liquid format (e.g., in PBS containing 50% glycerol, 0.5% BSA and 0.02% sodium azide), limited short-term storage at 4°C is acceptable.
When working with sodium azide-containing antibodies, remember this is a hazardous substance that should be handled by trained personnel only .
A robust validation protocol should include:
Positive and negative controls: Use tissues/cells known to express or not express OR8H3.
Western blot analysis: Verify a single band of the expected molecular weight (~36 kDa for OR8H3).
Peptide competition assay: Pre-incubate the antibody with the immunizing peptide to confirm specificity.
Knockout/knockdown validation: Compare staining in OR8H3 knockout or knockdown samples versus wild-type.
Cross-reactivity testing: If working with multiple species, confirm species-specific activity as documented in product datasheets.
Secondary antibody-only control: To account for background staining from the detection system.
This systematic approach ensures that observed signals are genuinely attributable to OR8H3 .
Harvest cells or tissues and lyse in a buffer containing protease inhibitors.
Centrifuge (>3000 x g) to remove debris.
Determine protein concentration.
Denature samples with a reducing agent at 95°C for 5 minutes.
Load 20-50 μg of protein per lane for detection.
Fix cells or tissue sections with 4% paraformaldehyde.
Permeabilize with 0.1-0.5% Triton X-100.
Block with 1-5% BSA or serum.
Incubate with OR8H3 antibody at 1:200-1:1000 dilution.
Detect with fluorophore-conjugated secondary antibody.
Coat plates with capture antibody or antigen.
Block with appropriate buffer.
Add samples and standards.
Use OR8H3 antibody at 1:10000 dilution for detection.
Develop with appropriate substrate system.
These protocols should be optimized based on your specific research requirements .
Recent advances in AI technologies are transforming antibody design:
De novo generation: AI can generate antigen-specific antibody CDRH3 sequences using germline-based templates, potentially bypassing traditional experimental approaches .
Binding prediction: Machine learning models predict antibody-antigen binding by analyzing many-to-many relationships between antibodies and antigens, though challenges remain with out-of-distribution predictions .
Active learning strategies: Novel active learning algorithms can improve experimental efficiency by up to 35% in antibody-antigen binding prediction, reducing the required number of experiments .
Complementarity to traditional methods: AI approaches mimic natural antibody generation outcomes while bypassing the complexity, offering efficient alternatives to traditional experimental discovery methods .
These technologies could significantly reduce the time and resources required for developing highly specific antibodies against challenging targets like olfactory receptors .
The study of ultralong CDR3H regions presents several challenges:
Structural complexity: Bovine CDR3H lengths can span 5-72 residues, with those >48 residues classified as "ultralong." These structures may interact with epitopes typically inaccessible to conventional antibodies .
Diversification mechanisms: Unlike humans and mice where immunoglobulin diversity comes from recombination, cattle achieve diversity through CDR3H length heterogeneity and somatic hypermutation independent of antigenic contact .
Library design considerations: When designing phage display or other antibody libraries targeting OR8H3, researchers must consider CDR3H length variability to ensure comprehensive epitope coverage.
Species-specific approaches: The structural differences between human and bovine antibodies necessitate species-specific approaches when developing antibodies against targets like OR8H3 .
Understanding these unique structural features can inform the design of novel antibodies with enhanced specificity and affinity for olfactory receptors like OR8H3 .
Distinguishing between closely related olfactory receptors requires careful experimental design:
Epitope selection: Target unique regions that differ between OR8H3 and OR8B2/OR8B3. Sequence alignment analysis is essential for identifying these regions.
Antibody validation: Perform cross-reactivity studies with recombinant proteins or cells expressing only one receptor type.
Competitive binding assays: Use peptides specific to OR8H3 or OR8B2/B3 to demonstrate antibody specificity.
Gene editing controls: Create knockout or knockin cell lines expressing only one receptor for definitive validation.
Sequential immunoprecipitation: Deplete samples of one receptor type before probing for the other.
The OR8B2/OR8B3 antibody (PACO03849) targets the internal region of human Olfactory receptor 8B2/3 , so researchers should be cautious when studying tissues where multiple olfactory receptors are expressed to avoid cross-reactivity issues.
| Issue | Possible Causes | Solutions |
|---|---|---|
| No signal | Insufficient antigen | Increase protein load (50-100 μg) |
| Degraded antibody | Use fresh aliquot stored at -20°C/-80°C | |
| Incorrect dilution | Try 1:500 dilution for stronger signal | |
| Multiple bands | Cross-reactivity | Use more stringent washing |
| Protein degradation | Add fresh protease inhibitors | |
| Non-specific binding | Increase blocking time/concentration | |
| High background | Insufficient blocking | Extend blocking to 2 hours |
| Excessive antibody | Dilute primary antibody further (1:2000) | |
| Inadequate washing | Increase wash volume and duration |
Remember that OR8H3 is a transmembrane protein, so sample preparation must preserve its native structure while allowing for efficient transfer to membranes .
For quantitative assessment of OR8H3 expression:
ELISA-based quantification: The OR8H3 ELISA Kit (ABIN1743686) offers a detection range of 50-1000 pg/mL with a minimum detection limit of 50 pg/mL and sensitivity of 1.0 pg/mL. This competitive ELISA is suitable for cell culture supernatant, plasma, serum, and tissue homogenate samples .
RT-qPCR methodology: Design primers specific to OR8H3 mRNA for transcriptional analysis, ensuring they don't amplify highly similar family members.
Quantitative Western blotting: Use known quantities of recombinant OR8H3 to generate a standard curve for densitometric analysis.
Flow cytometry: For cellular expression analysis, particularly in heterogeneous samples.
Immunohistochemistry with digital image analysis: For spatial distribution and quantitative assessment in tissue sections.
Each method has advantages and limitations, so researchers often employ multiple approaches for comprehensive quantification .
When working with OR8H3 antibodies across species:
Verify cross-reactivity profile: Check the product datasheet for validated species. Some OR8H3 antibodies work only with human samples , while others have broader reactivity including cow, dog, guinea pig, horse, mouse, pig, rabbit, and rat .
Sequence homology assessment: Compare the OR8H3 sequence homology between your species of interest and the immunogen used to generate the antibody.
Epitope conservation: Analyze whether the specific epitope (e.g., C-terminal region) is conserved across species.
Validation in each species: Perform species-specific positive and negative controls.
Dilution optimization: Optimal dilutions may vary between species; perform a dilution series when adapting to a new species.
Detection system compatibility: Ensure secondary antibodies are appropriate for the host species of your samples.
These considerations help ensure reliable results when applying OR8H3 antibodies to comparative studies across different species .
Recent research has shown promising developments in active learning for antibody-antigen binding prediction:
Efficiency improvements: Active learning strategies can reduce the number of required antigen mutant variants by up to 35% and accelerate the learning process by 28 steps compared to random baseline approaches .
Out-of-distribution prediction: These algorithms address the challenge of predicting binding when test antibodies and antigens aren't represented in training data, which is particularly valuable for olfactory receptors with limited experimental data .
Cost reduction: By starting with small labeled subsets and iteratively expanding datasets, active learning can significantly reduce experimental costs while maintaining prediction accuracy .
Library-on-library approaches: Novel algorithms support many-to-many relationship analysis between antibodies and antigens, ideal for high-throughput screening of OR8H3 interactions .
These computational approaches could dramatically accelerate OR8H3 research by guiding experimental design and reducing resource requirements for discovering specific antibody-antigen interactions .
While the search results don't directly address OR8H3's role in disorders, we can consider several research directions:
Association with frontal sinusitis: GeneCards indicates OR8H3 is associated with frontal sinusitis, suggesting potential involvement in inflammatory nasal conditions .
Olfactory signaling pathway: OR8H3 participates in the olfactory signaling pathway, making it relevant to disorders involving smell perception deficits .
Therapeutic targeting: Antibodies against OR8H3 could serve as tools for studying olfactory disorders and potentially as diagnostic markers.
Comparative studies: Research comparing OR8H3 with its important paralog OR8H2 might reveal functional redundancies or specializations relevant to disease states .
Sensory biology applications: As noted for similar receptors like OR8B2/OR8B3, antibodies against these proteins enable detection and analysis in different cell types, making them valuable for studies in sensory biology and olfactory research .
Future research should explore these connections to develop novel diagnostic and therapeutic approaches for olfactory disorders.
For rigorous immunostaining experiments using OR8H3 antibodies:
Positive tissue control: Include tissues known to express OR8H3 (olfactory epithelium).
Negative tissue control: Include tissues known not to express OR8H3.
Absorption control: Pre-incubate antibody with immunizing peptide to demonstrate specificity.
Isotype control: Use non-specific IgG from the same host species at the same concentration.
Secondary antibody-only control: Omit primary antibody to assess background from secondary antibody.
Endogenous peroxidase/fluorescence control: Include steps to quench endogenous signals.
Dilution series: Test multiple antibody concentrations (1:200-1:1000 for IF) to determine optimal signal-to-noise ratio .
These controls help distinguish specific OR8H3 staining from background or non-specific binding, particularly important when studying tissues with potentially low expression levels.
An integrated experimental approach might include:
Expression-function correlation: Combine OR8H3 antibody detection with calcium imaging or electrophysiological recordings to correlate expression levels with olfactory neuron responses.
Co-localization studies: Use OR8H3 antibodies alongside markers for:
Signal transduction components (Gαolf, ACIII)
Neuronal maturation markers
Other olfactory receptors
to understand the receptor's place in the olfactory network.
Temporal expression analysis: Track OR8H3 expression during development or following olfactory stimulation using antibody detection at defined timepoints.
Receptor trafficking studies: Combine OR8H3 antibodies with subcellular markers to track receptor internalization and recycling following ligand binding.
Ligand identification: Pair antibody-based expression confirmation with functional screening to identify specific odorants that activate OR8H3.
This multifaceted approach links molecular expression patterns to physiological function, providing a more comprehensive understanding of OR8H3's role in olfaction .