At2g18780 is a gene locus on chromosome 2 of Arabidopsis thaliana. This gene encodes a protein involved in plant cellular processes. When selecting antibodies for this protein, researchers should consider:
Expected molecular weight (varies depending on post-translational modifications)
Cellular localization pattern
Expression levels across different tissues and developmental stages
Relationship to homologous proteins that may cross-react with antibodies
When planning experiments, compare antibody specifications with published genomic and proteomic data to ensure alignment with expected protein characteristics.
Antibody validation is critical given widespread concerns about antibody specificity. Research has shown that many commercially available antibodies exhibit nonspecific binding patterns, making validation essential . Recommended validation approaches include:
Western blot analysis comparing:
Wild-type plants
At2g18780 knockout or knockdown mutants
Tissues with differential expression patterns
Immunohistochemistry controls:
Omission of primary antibody
Pre-immune serum controls
Peptide competition assays
Comparison with fluorescent protein fusion localization
Additional validation methods:
RNA interference to confirm specificity
Heterologous expression systems
Multiple antibodies targeting different epitopes
Validation across different experimental techniques is recommended, as antibodies may perform differently depending on the application .
At2g18780 antibodies can be used in various research applications:
Application | Common Dilution | Recommended Controls | Special Considerations |
---|---|---|---|
Western blot | 1:1,000-1:10,000 | Knockout mutant, loading control | Confirm band size matches predicted MW |
Immunohistochemistry | 1:100-1:500 | No primary, peptide competition | Optimize fixation method |
Immunoprecipitation | 1:50-1:200 | IgG control, input sample | Buffer optimization crucial |
ChIP | 1:50-1:100 | IgG control, non-target region | Crosslinking optimization |
ELISA | 1:1,000-1:5,000 | Standard curve, blank wells | Validate with recombinant protein |
Each application requires specific optimization. When using global antibodies that recognize multiple homologs, additional controls may be needed to distinguish specific signals .
Proper storage and handling significantly impact antibody performance:
Store lyophilized antibodies at -20°C until reconstitution
Once reconstituted, make small aliquots to avoid repeated freeze-thaw cycles
Store reconstituted antibodies at -20°C for long-term storage
Spin tubes briefly before opening to collect all material
Track antibody lot numbers, as performance may vary between batches
Maintain a validation record for each antibody lot
Consider adding preservatives for antibodies stored at 4°C
Improper storage can lead to degradation, aggregation, and loss of specificity, potentially explaining inconsistent experimental results.
Cross-reactivity is a common challenge, particularly with plant proteins that may have multiple isoforms. Studies have shown that antibodies often recognize multiple immunoreactive bands, including in knockout organisms lacking the target protein :
Analytical approaches:
Mass spectrometry identification of detected bands
Preabsorption with potential cross-reactive proteins
Epitope mapping to identify shared sequence regions
Experimental solutions:
Use antibodies raised against unique protein regions
Implement knockout/knockdown controls in every experiment
Compare results from multiple antibodies targeting different epitopes
Data analysis strategies:
Document all observed bands/signals
Compare with predicted molecular weights
Consider post-translational modifications affecting mobility
Research on other plant antibodies demonstrates that identical immunoreactive patterns can be present in both wild-type and knockout mice, highlighting the critical importance of proper controls .
Several factors influence immunolocalization results:
Fixation methods significantly impact epitope preservation:
Aldehyde fixatives (formaldehyde, glutaraldehyde) preserve structure but may mask epitopes
Organic solvents (methanol, acetone) may better preserve some epitopes but disrupt membranes
Empirical testing of multiple fixation protocols is recommended
Tissue-specific considerations:
Plant cell walls require optimized permeabilization
Autofluorescence varies across tissues and can interfere with detection
Background staining patterns differ between tissue types
Antibody-specific factors:
Studies examining antibodies raised against different domains of proteins show that immunostaining patterns can differ significantly between antibodies targeting the same protein .
Distinguishing between closely related proteins requires careful experimental design:
Epitope selection strategy:
Target unique protein regions for antibody production
Analyze sequence homology to identify distinguishing peptides
Consider raising antibodies against post-translational modifications unique to specific isoforms
Genetic approaches:
Use isoform-specific knockout/knockdown lines
Perform complementation with specific isoforms
Create tagged versions of individual isoforms
Biochemical methods:
2D gel electrophoresis to separate based on both size and charge
Ion exchange chromatography prior to immunoblotting
Isoform-specific enzymatic assays when applicable
Advanced detection methods:
Mass spectrometry for isoform-specific peptide identification
Proximity ligation assays for in situ detection
Single-molecule imaging to detect co-localization patterns
Combining multiple approaches provides the most robust isoform discrimination strategy.
Post-translational modifications (PTMs) can significantly alter antibody binding:
Common PTMs affecting antibody recognition:
Phosphorylation
Glycosylation
Ubiquitination
Sumoylation
Proteolytic processing
Experimental considerations:
Use phosphatase treatment to assess phosphorylation effects
Compare reducing vs. non-reducing conditions for disulfide-dependent epitopes
Consider modification-specific antibodies for studying specific PTM states
Analytical approaches:
Include PTM prediction in experimental design
Use mass spectrometry to identify actual modifications
Consider multiple antibodies targeting different protein regions
PTMs can explain why antibodies recognize bands of unexpected molecular weights in immunoblotting experiments.
Optimizing Western blot conditions:
Sample preparation:
Include protease inhibitors to prevent degradation
Denature samples completely (95°C for 5 minutes in sample buffer)
Load appropriate protein amounts (typically 10-30 μg total protein)
Gel electrophoresis:
Select appropriate gel percentage based on protein size
Include molecular weight markers
Consider gradient gels for better resolution
Transfer conditions:
Optimize transfer time and voltage for the protein size
Verify transfer efficiency with reversible staining
Choose appropriate membrane (PVDF or nitrocellulose)
Antibody incubation:
Expected molecular weight should be confirmed against protein databases and may vary depending on post-translational modifications.
Sample preparation significantly impacts detection quality:
Tissue selection and harvesting:
Consider developmental stage and expression timing
Harvest at consistent times to control for circadian variation
Flash-freeze samples immediately after collection
Extraction buffer optimization:
Test different detergent types and concentrations
Include appropriate protease inhibitors
Consider phosphatase inhibitors if studying phosphorylated forms
Homogenization methods:
Cryogenic grinding for tough plant tissues
Gentle methods for preserving protein complexes
Sonication for difficult-to-extract proteins
Fractionation considerations:
Separate subcellular fractions if studying localization
Consider detergent solubility when analyzing membrane proteins
Include controls for fraction purity
For experimental reproducibility, all samples should be processed using identical protocols and within the same experimental session when possible.
Essential controls for co-immunoprecipitation (co-IP) experiments:
Input controls:
Total lysate sample before IP (typically 5-10%)
Quantitative analysis of target protein in input
Negative controls:
Non-immune IgG or pre-immune serum
Lysate from knockout/knockdown plants
Competitive elution with immunizing peptide
Specificity controls:
Reverse IP with antibodies against suspected interaction partners
Size-exclusion chromatography to confirm complex formation
Chemical crosslinking to stabilize transient interactions
Technical controls:
No-antibody beads to assess non-specific binding
Denaturing elution to ensure complete recovery
Quantification of unbound fraction
These controls help distinguish genuine interactions from technical artifacts that frequently complicate co-IP experiments.
When facing inconsistent antibody results:
Systematic evaluation of variables:
Antibody lot variation (request validation data from suppliers)
Sample preparation inconsistencies
Protocol drift over time
Equipment calibration issues
Experimental design modifications:
Increase biological and technical replicates
Implement standardized positive and negative controls
Document all protocol details meticulously
Analytical approaches:
Quantitative analysis with appropriate normalization
Statistical assessment of variability
Blinded analysis to reduce bias
Alternative approaches:
Try different antibodies targeting the same protein
Complement with non-antibody techniques (e.g., fluorescent protein tagging)
Consider mass spectrometry for unbiased protein identification
Studies have shown that different antibodies against the same protein can yield variable results, emphasizing the importance of comprehensive validation .
When different studies show conflicting localization patterns:
Methodological analysis:
Compare fixation and permeabilization methods
Assess antibody specificity under each condition
Consider resolution limitations of imaging techniques
Biological explanations:
Dynamic protein localization depending on cell state
Developmental regulation of localization
Stimulus-dependent protein translocation
Isoform-specific localization patterns
Integration strategies:
Combine multiple detection methods
Use live-cell imaging to capture dynamic changes
Employ super-resolution microscopy for detailed localization
Research on other antibodies has shown that immunostaining patterns can differ dramatically between antibodies targeting different domains of the same protein , requiring careful interpretation of results.
To ensure reproducibility and reliability, publications should include:
Antibody validation data:
Specificity controls (especially knockout/knockdown validation)
Expected versus observed molecular weights
Cross-reactivity assessment
Batch/lot information
Detailed methodology:
Complete sample preparation protocol
Buffer compositions
Incubation times and temperatures
Image acquisition settings
Quantification approach:
Raw images before processing
Quantification methods with statistical analysis
Normalization procedures
Sample size and power calculations
Controls and replicates:
All control experiments performed
Number of biological and technical replicates
Any outliers and how they were handled
Thorough reporting ensures that results can be properly evaluated and reproduced by other researchers in the field.
Emerging techniques offer new opportunities:
Proximity labeling approaches:
BioID or TurboID fusion proteins for in vivo interaction mapping
APEX2 for ultrastructural localization
Split-protein complementation for direct interaction validation
Advanced imaging methods:
Super-resolution microscopy for precise localization
Light-sheet microscopy for 3D tissue imaging
FRET/FLIM for in vivo interaction studies
Single-cell approaches:
Single-cell proteomics
In situ protein detection in specific cell types
Spatial transcriptomics to correlate protein and mRNA localization
Computational tools:
Machine learning for image analysis
Protein structure prediction to identify accessible epitopes
Network analysis of protein interactions
These emerging approaches can complement traditional antibody-based methods to provide more comprehensive understanding of protein function.
Integrative approaches enhance research value:
Multi-omics integration strategies:
Correlate protein levels with transcriptomics data
Integrate phosphoproteomics for functional state analysis
Combine with metabolomics for pathway analysis
Data integration tools:
Pathway mapping algorithms
Protein-protein interaction networks
Gene ontology enrichment analysis
Validation approaches:
Genetic manipulation to confirm functional predictions
Heterologous expression systems
In vitro biochemical assays