KEGG: osa:4333794
UniGene: Os.12106
Os03g0694000 Antibody (product code CSB-PA774630XA01OFG) is a polyclonal antibody that targets the protein encoded by the Os03g0694000 gene in Oryza sativa subsp. japonica (rice), associated with UniProt number Q851K1 . This antibody is used in research applications to study protein expression, localization, and function in rice. The antibody is available in different sizes (0.2mg, 10mg) and is designed for immunological research applications . Unlike therapeutic antibodies, which target human proteins for medical treatments, Os03g0694000 Antibody is specifically developed for plant science research to investigate rice protein function and expression patterns.
Based on standard validation protocols for plant antibodies, Os03g0694000 Antibody is likely validated for several research applications including:
Western blotting (protein detection in cell/tissue lysates)
Immunoprecipitation (protein isolation from complex mixtures)
Immunohistochemistry/Immunofluorescence (protein localization in tissue sections)
Each application requires specific validation parameters. For Western blotting, researchers should expect documentation of specific band detection at the expected molecular weight. For immunohistochemistry, appropriate controls demonstrating specificity in plant tissues should be provided . When planning experiments, researchers should review the validation data provided by the manufacturer to confirm suitability for their specific application.
The Os03g0694000 Antibody is primarily developed for Oryza sativa subsp. japonica, but may exhibit cross-reactivity with homologous proteins in other rice subspecies such as Oryza sativa subsp. indica . Cross-reactivity depends on protein conservation across subspecies. When studying proteins across different rice varieties, researchers should perform preliminary validation experiments to determine specificity in their particular rice subspecies . This validation should include positive and negative controls from each subspecies being studied to verify antibody performance and specificity. Sequence alignment of the target protein across subspecies can help predict potential cross-reactivity.
Effective sample preparation for Os03g0694000 detection requires:
For protein extraction:
Grind tissue in liquid nitrogen to fine powder
Extract using buffer containing 50mM Tris-HCl (pH 8.0), 150mM NaCl, 1% NP-40, and protease inhibitors
Centrifuge at 12,000g for 15 minutes at 4°C
For immunohistochemistry:
Fix tissue in 4% paraformaldehyde
Embed in paraffin or freeze in OCT compound
Section tissues (5-10μm thickness)
Deparaffinize and rehydrate sections
Perform antigen retrieval (citrate buffer pH 6.0 recommended)
Block with 3-5% BSA or normal serum
These protocols may require optimization based on specific research objectives and tissue types. For cold-stressed samples, immediate processing is crucial to preserve protein modifications that may occur during stress responses .
Optimizing western blot conditions for Os03g0694000 Antibody requires systematic testing of several parameters:
Antibody dilution: Start with manufacturer's recommended dilution (typically 1:1000) and test a range (1:500 to 1:5000)
Blocking solution: Test 5% non-fat milk vs. 3-5% BSA in TBST
Incubation time and temperature: Compare overnight at 4°C vs. 2 hours at room temperature
Wash stringency: Optimize number and duration of TBST washes
Detection method: HRP-conjugated secondary antibody with chemiluminescence is generally recommended
A titration experiment testing multiple antibody concentrations is essential to determine the optimal signal-to-noise ratio. Additionally, include positive controls (purified recombinant protein or overexpression samples) and negative controls (knockout or knockdown samples if available) to verify specificity .
For successful immunoprecipitation with Os03g0694000 Antibody, consider:
Pre-clearing step: Incubate lysate with protein A/G beads before adding antibody to reduce non-specific binding
Antibody amount: Use 2-5μg antibody per 500μg total protein
Incubation conditions: Rotate samples at 4°C overnight with pre-washed antibody beads
Wash buffer composition: NETN buffer (20mM Tris-HCl, 100mM NaCl, 1mM EDTA, 0.5% NP-40, pH 8.0) is effective for plant samples
Elution method: Elute with 0.1% trifluoroacetic acid or SDS loading buffer
For co-immunoprecipitation studies to identify interaction partners, gentler lysis and wash conditions may be required to preserve protein-protein interactions. Crosslinking prior to lysis may stabilize transient interactions. Validation through reciprocal immunoprecipitation with antibodies against suspected interaction partners strengthens findings .
Verifying antibody specificity is critical for reliable results. Implement these validation strategies:
Positive controls: Use purified recombinant Os03g0694000 protein or overexpression systems
Negative controls: Include:
Knockout/knockdown samples when available
Pre-immune serum controls
Peptide competition assays (pre-incubating antibody with immunizing peptide)
Expected molecular weight verification: Compare observed band size with theoretical predictions
Multiple detection methods: Confirm findings using alternative techniques (e.g., mass spectrometry)
For plant systems specifically, testing antibody reactivity in related species with known sequence divergence can provide additional evidence of specificity. Documentation of all validation experiments should be maintained for publication purposes .
For accurate quantification across conditions:
Normalization strategy: Use multiple housekeeping proteins (e.g., actin, tubulin, GAPDH) validated for stability under your experimental conditions
Technical replicates: Perform at least three technical replicates per biological sample
Biological replicates: Include minimum 3-5 independent biological replicates
Standard curve: For absolute quantification, include purified protein standards
Image analysis: Use software like ImageJ with background subtraction for densitometry
Statistical analysis: Apply appropriate tests (t-test, ANOVA) with corrections for multiple comparisons
When studying stress responses, such as cold treatment, time-course experiments are valuable to capture dynamic changes in protein expression. Additionally, measuring both protein and transcript levels can reveal post-transcriptional regulation mechanisms .
Interpretation of subcellular localization data requires:
Fraction purity verification: Use established markers for each subcellular compartment (e.g., histone H3 for nucleus, RuBisCO for chloroplast)
Quantitative comparison: Calculate enrichment factors relative to whole-cell lysate
Confocal microscopy validation: Confirm fractionation results with immunofluorescence microscopy
Context of known function: Interpret localization in light of protein's predicted domains and functions
In rice stress response studies, proteins may shuttle between compartments, so monitoring localization changes over time after treatment is informative. Nuclear-cytoplasmic partitioning is particularly relevant for regulatory proteins. Based on search results, approximately 45% of differentially ubiquitin-modified proteins in cold-stressed rice are located in chloroplasts, suggesting the importance of evaluating chloroplast fractions when studying stress responses .
When confronting weak or absent signals:
Antibody functionality check: Test antibody on positive control samples
Protein extraction efficiency: Verify protein recovery with Bradford assay and Coomassie staining
Antigen retrieval optimization: For fixed tissues, test multiple antigen retrieval methods
Signal amplification: Consider using:
Higher antibody concentration
Extended incubation time
More sensitive detection systems (e.g., enhanced chemiluminescence)
Protein modification interference: Check if post-translational modifications affect epitope recognition
If ubiquitination is suspected to affect antibody binding, as seen in cold-stressed rice samples, treatment with deubiquitinating enzymes prior to immunoblotting may improve detection. Additionally, confirming target protein expression at the transcript level can help determine if the issue is technical or biological .
To distinguish specific from non-specific signals:
Molecular weight verification: Compare observed band size with theoretical prediction
Peptide competition assay: Pre-incubate antibody with immunizing peptide to block specific binding
Secondary antibody only control: Identify signals arising from secondary antibody alone
Knockout/knockdown validation: Test samples with reduced or absent target expression
Multiple antibodies comparison: If available, use antibodies targeting different epitopes of the same protein
For plant proteins with multiple isoforms or family members, careful analysis of predicted molecular weights for each variant is essential. Researchers should consult protein databases to identify potential cross-reactive proteins with similar epitopes and molecular weights .
Before using a new antibody batch:
Certificate of analysis review: Check purity (>90% for research applications)
SDS-PAGE analysis: Verify antibody integrity by confirming expected heavy (50 kDa) and light (25 kDa) chain bands
ELISA titer comparison: Compare sensitivity against previous batches
Standard sample testing: Run parallel tests with old and new batches on identical samples
Mass spectrometry verification: For critical applications, confirm antibody identity by intact protein mass spectrometry
Mass spectrometry analysis should reveal defined signals for light (approximately 23.7 kDa) and heavy chains (approximately 49.9 kDa), indicating monoclonal origin. Multiple signals for heavy chains with mass differences of 162 Da may indicate glycosylation variants, which are normal post-translational modifications .
For studying post-translational modifications (PTMs):
Co-immunoprecipitation with modification-specific antibodies: Use Os03g0694000 Antibody for IP followed by blotting with anti-ubiquitin, anti-phospho, or other PTM-specific antibodies
Two-dimensional gel electrophoresis: Separate proteins by isoelectric point and molecular weight to resolve modified forms
PhosTag™ gels: For phosphorylation studies, use PhosTag™ acrylamide to separate phosphorylated from non-phosphorylated forms
Mass spectrometry analysis: After immunoprecipitation, perform LC-MS/MS analysis to identify precise modification sites
Integration of multi-omics data requires:
Correlation analysis: Calculate Pearson/Spearman correlation between transcript and protein levels across conditions
Temporal dynamics analysis: Compare time-course patterns of transcript and protein changes
Pathway enrichment: Map differentially expressed genes and proteins to known stress response pathways
Network analysis: Construct protein-protein interaction networks incorporating Os03g0694000
Differential regulation identification: Highlight cases where transcript and protein levels are discordant, suggesting post-transcriptional regulation
Cold stress research in rice has identified glutathione metabolism as an enriched pathway in differentially ubiquitin-modified proteins, with glutathione peroxidase (OsGPX1) being involved in cold tolerance. If Os03g0694000 interacts with components of this pathway, investigating these connections could reveal its role in stress tolerance mechanisms .
For developing custom monoclonal antibodies:
Antigen design considerations:
Select unique, surface-exposed epitopes (15-20 amino acids)
Avoid regions with post-translational modifications
Target regions with low homology to related proteins
Immunization strategy:
Use multiple mice to increase diversity of antibody response
Employ TiterFast™ adjuvant to reduce immunization time (22-43 days vs. conventional 60 days)
Hybridoma screening workflow:
Primary screening: ELISA against immunizing peptide/protein
Secondary screening: Application-specific tests (Western, IHC)
Tertiary screening: Cross-reactivity testing with related proteins
Clone selection and validation:
For critical research applications, developing antibody blends combining multiple clones recognizing different epitopes can improve detection sensitivity and specificity. Evidence suggests that blends containing antibodies to distinct epitopes or of different isotypes (e.g., IgG1 and IgG3) may provide superior functionality compared to individual antibodies .
When conducting comparative analysis:
Sequence alignment: Perform multiple sequence alignment of Os03g0694000 with homologs from other species
Domain conservation analysis: Identify conserved functional domains and variable regions
Cross-species antibody reactivity testing: Test Os03g0694000 Antibody against proteins from:
Zea mays (corn)
Triticum aestivum (wheat)
Hordeum vulgare (barley)
Other cereals and model plants
Functional complementation studies: Express Os03g0694000 in heterologous systems or mutants of other species to assess functional conservation
Based on available cross-reactivity data for similar rice antibodies, Os03g0694000 Antibody may recognize homologous proteins in closely related grass species like Zea mays, Triticum aestivum, Hordeum vulgare, Panicum virgatum, and Sorghum bicolor. This cross-reactivity can be leveraged for comparative studies across species .
For stress response network studies:
Controlled stress application:
Standardize stress intensity and duration
Monitor physiological indicators of stress (e.g., membrane leakage, ROS production)
Time-course sampling:
Include multiple timepoints (0h, 6h, 24h, recovery phase)
Preserve samples appropriately for multiple analyses
Multi-level analysis:
Transcriptome (RNA-seq)
Proteome (antibody-based and MS-based)
Protein modifications (phosphoproteome, ubiquitylome)
Network reconstruction:
Research on cold-stressed rice shows significant changes in protein expression and ubiquitination patterns after 24 hours of cold treatment. The comparison of control and overexpression lines reveals distinct protein signatures that correlate with stress tolerance. When designing similar experiments with Os03g0694000, these temporal dynamics should be considered .
For integration with QTL research:
Genetic mapping correlation:
Determine if Os03g0694000 is located within known stress-related QTLs
Analyze SNPs or other variations in Os03g0694000 across varieties with different stress tolerance
Phenotype-genotype association:
Correlate Os03g0694000 expression/modification levels with stress tolerance phenotypes
Test multiple rice varieties with natural variations in Os03g0694000
CRISPR-based validation:
Create targeted modifications in Os03g0694000
Assess impact on stress tolerance phenotypes
Marker-assisted selection:
Cold tolerance QTLs have been identified in rice, including ctb-1 (Os04g0619400) and ctb-2 (Os04g0603000), which co-localize with glutathione peroxidase OsGPX1. Investigating potential interactions between Os03g0694000 and these known QTLs could reveal its role in cold tolerance mechanisms and provide targets for crop improvement .
| Parameter | Condition A | Condition B | Condition C | Recommended |
|---|---|---|---|---|
| Antibody Dilution | 1:500 | 1:1000 | 1:2000 | 1:1000 |
| Blocking Agent | 5% Milk in TBST | 3% BSA in TBST | 5% BSA in TBST | 3% BSA in TBST |
| Incubation Time | 1h at RT | 3h at RT | Overnight at 4°C | Overnight at 4°C |
| Wash Buffer | TBST (0.05% Tween) | TBST (0.1% Tween) | PBST (0.1% Tween) | TBST (0.1% Tween) |
| Secondary Antibody | 1:5000 | 1:10000 | 1:20000 | 1:10000 |
| Detection System | Standard ECL | Enhanced ECL | Fluorescent | Enhanced ECL |
| Species | Protein Homology (%) | Expected Cross-Reactivity | Validated |
|---|---|---|---|
| Oryza sativa subsp. japonica | 100 | Strong | Yes |
| Oryza sativa subsp. indica | 90-95 | Strong | Yes |
| Zea mays | 75-80 | Moderate | Predicted |
| Triticum aestivum | 70-75 | Moderate | Predicted |
| Hordeum vulgare | 65-70 | Weak-Moderate | Predicted |
| Sorghum bicolor | 70-75 | Moderate | Predicted |
| Arabidopsis thaliana | 40-50 | Weak/None | Unlikely |
| Brassica rapa | 35-45 | Weak/None | Unlikely |
| Fraction | Marker Protein | Expected Enrichment | Os03g0694000 Detection |
|---|---|---|---|
| Nuclear | Histone H3 | 15-20x | To be determined |
| Chloroplast | RuBisCO LSU | 25-30x | To be determined |
| Mitochondrial | Cytochrome c | 12-15x | To be determined |
| Cytosolic | GAPDH | 4-5x | To be determined |
| Membrane | Plasma membrane ATPase | 8-10x | To be determined |
| Endoplasmic Reticulum | BiP | 10-12x | To be determined |
Integration of Os03g0694000 research findings requires:
Contextualizing within stress response pathways:
Place Os03g0694000 in established signaling networks
Identify upstream regulators and downstream targets
Connect to physiological and phenotypic outcomes
Cross-disciplinary integration:
Combine with metabolomic data to link to biochemical pathways
Integrate with structural biology to understand protein function
Connect to field-level phenotyping for agricultural relevance
Knowledge dissemination:
Deposit comprehensive datasets in public repositories
Report detailed methodologies for reproducibility
Contribute to plant protein interaction databases
Translational applications: