CSTA antibodies are immunoglobulins raised against specific epitopes of the CSTA protein. They are categorized into monoclonal or polyclonal types, depending on their production method.
Target: CSTA, a 13.1 kDa protein (118 amino acids) with a His-tag in recombinant forms .
Epitopes: Recognize regions such as the C-terminal (aa 69–98) or full-length sequence .
Applications: ELISA, Western blot, immunohistochemistry (IHC), flow cytometry, and immunofluorescence .
CSTA antibodies are pivotal in elucidating CSTA’s roles in disease pathology and therapeutic mechanisms.
CSTA expression is altered in cancers, with antibodies used to correlate its levels with prognosis or treatment response.
Role: High CSTA expression in tumors associates with advanced pT stages and lymph node metastases .
Findings: CSTA-positive ESCC cells co-express Ki67 (proliferation marker), contrasting with normal epithelia .
Antibody Use: IHC and double staining (CSTA/Ki67) to map expression in tumor tissues .
Role: CSTA knockdown weakens tight junctions, exacerbating epithelial barrier dysfunction .
Findings: FK506 (immunosuppressant) restores CSTA expression in inflammatory environments .
CSTA antibodies aid in evaluating CSTA’s potential as a therapeutic target.
Mechanism: CSTA modulates cysteine protease activity (e.g., cathepsins B, H, L) .
Drug Synergy: CSTA enhances cisplatin efficacy in GC by sensitizing cells to apoptosis .
Apoptosis: CSTA enhances caspase activation, promoting cell death in GC .
Cell Adhesion: CSTA knockdown disrupts tight junctions (ZO-1, CDH1) in epithelial cells .
Drug Response: CSTA modulates cisplatin sensitivity via protease inhibition .
Therapeutic Development: CSTA’s role in enhancing drug efficacy and inhibiting metastasis warrants further exploration .
Diagnostic Biomarker: CSTA’s expression in lymph node metastases suggests potential as a prognostic marker .
Epithelial Barrier Research: CSTA’s interaction with tight junction proteins (e.g., ZO-1) in inflammatory conditions requires deeper study .
Cystatin A, also known as Stefin A (CSTA), is a cysteine protease inhibitor involved in multiple cellular processes and disease pathways. This protein is studied across various research contexts including inflammation, cancer biology, and dermatological disorders. Researchers use specific antibodies to detect, quantify, and characterize CSTA expression patterns and functions in biological systems .
Based on current research resources, CSTA antibodies are available in several configurations:
Antibody Type | Target Region | Host | Clonality | Applications | Reactivity |
---|---|---|---|---|---|
Anti-CSTA (C-Term) | AA 69-98 | Rabbit | Polyclonal | WB, IHC(p) | Human |
Anti-CSTA (Full length) | AA 1-98 | Rabbit | Polyclonal | WB, IHC, ELISA, IF | Human |
Anti-CSTA | Not specified | Mouse | Monoclonal | IHC, StM | Human |
Anti-CSTA (C-Term) | C-Terminal | Rabbit | Polyclonal | WB, IHC, ELISA, IF, ICC | Human, Mouse |
These variations allow researchers to select antibodies optimized for their specific experimental requirements and biological systems .
The epitope target significantly impacts antibody performance across different applications. C-terminal targeting antibodies (AA 69-98) may recognize specific structural elements but can be affected by protein folding or post-translational modifications. Full-length targeting antibodies (AA 1-98) typically provide broader epitope recognition but might show increased cross-reactivity with related proteins. When designing experiments, researchers should consider how protein conformation in their experimental system, potential post-translational modifications, and epitope accessibility in fixed versus native states might affect antibody binding and signal detection .
Selection should be guided by several critical factors:
Experimental application (WB, IHC, IF, ELISA)
Sample type (cell lysates, tissue sections, fixed vs. fresh)
Species reactivity requirements
Clonality preferences (monoclonal for specificity, polyclonal for sensitivity)
Target region considerations (C-terminal vs. full-length)
For meaningful validation, employ orthogonal approaches using multiple antibodies targeting different epitopes. This strategy helps confirm consistent results and enhances confidence in your experimental observations .
Implementing proper controls is critical for reliable interpretation of CSTA antibody experiments:
Positive controls: Tissues or cell lines with confirmed CSTA expression (e.g., certain skin epithelial cells)
Negative controls: Samples known to lack CSTA expression
Secondary antibody-only controls: Omit primary antibody to assess non-specific binding
Isotype controls: Use non-specific antibodies of the same isotype to detect Fc-mediated binding
Peptide competition: Pre-incubate antibody with immunizing peptide to verify specificity
Genetic validation: Compare staining patterns in CSTA-knockdown or knockout samples
These controls help distinguish specific signals from technical artifacts and validate experimental interpretations .
A multi-faceted validation approach includes:
Testing across multiple applications (WB, IHC, IF) to confirm consistent target recognition
Employing different antibodies targeting distinct CSTA epitopes
Conducting peptide competition assays
Performing antibody validation using CSTA-depleted samples
Confirming molecular weight consistency in Western blotting
Correlating protein detection with mRNA expression data
Analyzing immunoprecipitated proteins by mass spectrometry
For challenging experimental contexts:
For low-abundance detection: Consider signal amplification systems such as tyramide signal amplification or polymer-based detection methods
For fixed tissues with potential epitope masking: Test multiple antigen retrieval methods (heat-induced vs. enzymatic, varying pH conditions)
For multiplex applications: Select antibodies raised in different host species and carefully titrate to minimize cross-reactivity
For quantitative analysis: Establish standard curves using recombinant CSTA protein
For high background issues: Optimize blocking conditions, detergent concentrations, and washing protocols
Each optimization should be systematically documented to establish reproducible protocols for your specific experimental system .
When faced with discrepant results from different antibodies:
Epitope accessibility differences in various sample preparation methods
Post-translational modifications affecting epitope recognition
Recognition of different CSTA isoforms or splice variants
Lot-to-lot variability in commercial antibodies
Different cross-reactivity profiles with related cystatin family members
Variations in antibody affinity affecting detection thresholds
Method-specific compatibility issues
Rather than viewing these contradictions as experimental failures, consider them opportunities to discover novel aspects of CSTA biology, potentially revealing isoform-specific functions or regulatory mechanisms .
The performance of antibodies in detecting CSTA is significantly influenced by their biophysical characteristics. Recent research on antibody design demonstrates that optimal antibodies typically display:
Property | Optimal Range | Impact on Performance |
---|---|---|
Expression yield | >15 mg/L | Ensures sufficient material for experiments |
Monomer percentage | >95% | Reduces aggregation-related artifacts |
Thermal stability (Tm) | >70°C | Maintains activity during experimental conditions |
Non-specific binding (PSP) | <60 RFU | Improves signal-to-noise ratio |
Self-association (CS-SINS score) | <0.15 | Prevents false-positive aggregation results |
Antibodies with favorable biophysical profiles generally provide more consistent and reliable experimental results .
Systematic troubleshooting involves:
Antibody validation review: Reassess specificity through Western blotting or peptide competition
Protocol optimization: Systematically vary antibody concentration, incubation time/temperature, and buffer conditions
Sample preparation assessment: Evaluate fixation methods, protein extraction protocols, or storage conditions
Positive control verification: Confirm antibody functionality using samples with known CSTA expression
Lot-to-lot comparison: Test different antibody lots if inconsistencies persist
Cross-platform validation: Compare results across different detection methods
Consider biological variables: Assess whether inconsistencies reflect actual biological heterogeneity
Document all troubleshooting steps methodically to identify the specific variables affecting your results .
Non-specific binding can be mitigated through several strategies:
Optimize blocking protocols using different blocking agents (BSA, milk, serum)
Increase washing stringency (duration, buffer composition)
Pre-adsorb antibodies against tissues/cells lacking CSTA
Titrate antibody concentration to minimize background while maintaining specific signal
Add mild detergents to reduce hydrophobic interactions
Consider alternative secondary antibody formulations
Utilize computational analysis to distinguish specific from non-specific signal patterns
Research indicates that well-designed antibodies inherently exhibit low non-specific binding. Recent advancements in antibody engineering have focused on minimizing this issue through improved design strategies .
Robust statistical analysis requires:
Proper normalization: Use appropriate loading controls or housekeeping proteins
Sufficient replication: Include biological and technical replicates (minimum n=3)
Appropriate statistical tests:
Parametric tests (t-test, ANOVA) for normally distributed data
Non-parametric tests (Mann-Whitney, Kruskal-Wallis) for non-normal distributions
Multiple comparison corrections: Apply Bonferroni or FDR adjustments when conducting multiple tests
Effect size reporting: Include Cohen's d or similar metrics alongside p-values
Visualization: Use box plots or violin plots to represent distribution characteristics
Power analysis: Ensure adequate sample size for detecting biologically relevant differences
For complex experimental designs, consider consulting with a biostatistician to ensure appropriate analytical approaches .
Recent advances in deep learning demonstrate promising applications for antibody research:
Generative Adversarial Networks (GANs): Can produce novel antibody sequences with optimized properties
In-silico antibody design: Computational generation of antibodies with favorable biophysical characteristics
Performance prediction: Algorithms can forecast expression yield, thermal stability, and non-specific binding propensities
Structural modeling: Predict antibody-antigen interactions to optimize binding affinity
Research shows that GAN-generated antibodies can achieve comparable or superior performance metrics to traditional antibodies, including:
High expression yields (7.5-32.7 mg/L)
Excellent thermal stability (Tm values 61.6-90.4°C)
Low non-specific binding
Predominantly monomeric behavior (91.4-98.6% monomer content)
These technologies could revolutionize CSTA antibody development by reducing development time and enhancing performance characteristics .
Integration possibilities include:
Single-cell proteomics: Combining CSTA antibodies with mass cytometry or imaging mass cytometry
Spatial biology: Incorporating CSTA detection into multiplex spatial profiling platforms
CRISPR screening: Correlating genetic perturbations with CSTA protein expression
Organoid models: Studying CSTA expression patterns in 3D tissue models
Multi-omics integration: Correlating CSTA protein levels with transcriptomic, metabolomic, and epigenomic data
In vivo imaging: Developing CSTA-targeted probes for non-invasive imaging
AI-assisted image analysis: Using machine learning to quantify complex CSTA expression patterns
These integrative approaches provide opportunities to contextualize CSTA function within broader biological systems and disease processes .
For sustained research initiatives, evaluate:
Manufacturing consistency: Assess lot-to-lot reproducibility data
Stability profiles: Consider antibody shelf-life and storage requirements
Validation depth: Review comprehensive validation across multiple applications
Glycosylation and cysteine content: Antibodies lacking N-linked glycosylation sites and non-canonical cysteines typically show better stability and consistency
Clone availability: Ensure long-term availability of preferred clones
Reproducibility across laboratories: Review literature for consistent performance
Supplier technical support: Evaluate responsiveness to technical inquiries
According to experimental data, antibodies with optimal biophysical properties (high thermal stability, low self-association) generally provide more consistent results across extended research programs .
Cystatin A, also known as Stefin A, is a member of the cystatin superfamily, which encompasses proteins containing multiple cystatin-like sequences. These proteins are primarily known for their role as cysteine protease inhibitors. Cystatin A is particularly significant in human biology due to its involvement in various physiological and pathological processes.
Cystatin A is a small protein with a molecular weight of approximately 11 kDa. It functions as a cysteine protease inhibitor, forming tight complexes with enzymes such as papain and cathepsins B, H, and L . This inhibitory activity is crucial for regulating protease activity in various cellular processes, including protein degradation, immune response, and apoptosis.
Cystatin A is predominantly expressed in epithelial cells, particularly in the squamous epithelium, follicular dendritic cells in lymphoid tissues, thymic epithelial cells, liver cells, granulocytes, and basal epithelial cells in the prostate . It is also one of the precursor proteins of the cornified cell envelope in keratinocytes, playing a vital role in epidermal development and maintenance .
The expression levels of Cystatin A have been studied in various diseases, including cancer. It has been proposed as a potential prognostic and diagnostic marker for certain types of cancer due to its altered expression in tumor tissues . Additionally, Cystatin A’s role in inhibiting cysteine proteases makes it a potential therapeutic target for diseases involving excessive protease activity.
Mouse anti-human Cystatin A antibodies are monoclonal antibodies developed to specifically detect human Cystatin A. These antibodies are commonly used in various scientific applications, including Western blotting, immunohistochemistry, ELISA, and immunoprecipitation . They are valuable tools for studying the expression, localization, and function of Cystatin A in different biological contexts.