Experiment Types and Workflows
Overview
Adaptyv provides multiple experimental assay types for comprehensive protein characterization. Each experiment type has specific applications, workflows, and data outputs.
Binding Assays
Description
Measure protein-target interactions using biolayer interferometry (BLI), a label-free technique that monitors biomolecular binding in real-time.
Use Cases
- Antibody-antigen binding characterization
- Receptor-ligand interaction analysis
- Protein-protein interaction studies
- Affinity maturation screening
- Epitope binning experiments
Technology: Biolayer Interferometry (BLI)
BLI measures the interference pattern of reflected light from two surfaces:
- Reference layer - Biosensor tip surface
- Biological layer - Accumulated bound molecules
As molecules bind, the optical thickness increases, causing a wavelength shift proportional to binding.
Advantages:
- Label-free detection
- Real-time kinetics
- High-throughput compatible
- Works in crude samples
- Minimal sample consumption
Measured Parameters
Kinetic constants:
- KD - Equilibrium dissociation constant (binding affinity)
- kon - Association rate constant (binding speed)
- koff - Dissociation rate constant (unbinding speed)
Typical ranges:
- Strong binders: KD < 1 nM
- Moderate binders: KD = 1-100 nM
- Weak binders: KD > 100 nM
Workflow
- Sequence submission - Provide protein sequences in FASTA format
- Expression - Proteins expressed in appropriate host system
- Purification - Automated purification protocols
- BLI assay - Real-time binding measurements against specified targets
- Analysis - Kinetic curve fitting and quality assessment
- Results delivery - Binding parameters with confidence metrics
Sample Requirements
- Protein sequence (standard amino acid codes)
- Target specification (from catalog or custom request)
- Buffer conditions (standard or custom)
- Expected concentration range (optional, improves assay design)
Results Format
{
"sequence_id": "antibody_variant_1",
"target": "Human PD-L1",
"measurements": {
"kd": 2.5e-9,
"kd_error": 0.3e-9,
"kon": 1.8e5,
"kon_error": 0.2e5,
"koff": 4.5e-4,
"koff_error": 0.5e-4
},
"quality_metrics": {
"confidence": "high|medium|low",
"r_squared": 0.97,
"chi_squared": 0.02,
"flags": []
},
"raw_data_url": "https://..."
}
Expression Testing
Description
Quantify protein expression levels in various host systems to assess producibility and optimize sequences for manufacturing.
Use Cases
- Screening variants for high expression
- Optimizing codon usage
- Identifying expression bottlenecks
- Selecting candidates for scale-up
- Comparing expression systems
Host Systems
Available expression platforms:
- E. coli - Rapid, cost-effective, prokaryotic system
- Mammalian cells - Native post-translational modifications
- Yeast - Eukaryotic system with simpler growth requirements
- Insect cells - Alternative eukaryotic platform
Measured Parameters
- Total protein yield (mg/L culture)
- Soluble fraction (percentage)
- Purity (after initial purification)
- Expression time course (optional)
Workflow
- Sequence submission - Provide protein sequences
- Construct generation - Cloning into expression vectors
- Expression - Culture in specified host system
- Quantification - Protein measurement via multiple methods
- Analysis - Expression level comparison and ranking
- Results delivery - Yield data and recommendations
Results Format
{
"sequence_id": "variant_1",
"host_system": "E. coli",
"measurements": {
"total_yield_mg_per_l": 25.5,
"soluble_fraction_percent": 78,
"purity_percent": 92
},
"ranking": {
"percentile": 85,
"notes": "High expression, good solubility"
}
}
Thermostability Testing
Description
Measure protein thermal stability to assess structural integrity, predict shelf-life, and identify stabilizing mutations.
Use Cases
- Selecting thermally stable variants
- Formulation development
- Shelf-life prediction
- Stability-driven protein engineering
- Quality control screening
Measurement Techniques
Differential Scanning Fluorimetry (DSF):
- Monitors protein unfolding via fluorescent dye binding
- Determines melting temperature (Tm)
- High-throughput capable
Circular Dichroism (CD):
- Secondary structure analysis
- Thermal unfolding curves
- Reversibility assessment
Measured Parameters
- Tm - Melting temperature (midpoint of unfolding)
- ΔH - Enthalpy of unfolding
- Aggregation temperature (Tagg)
- Reversibility - Refolding after heating
Workflow
- Sequence submission - Provide protein sequences
- Expression and purification - Standard protocols
- Thermostability assay - Temperature gradient analysis
- Data analysis - Curve fitting and parameter extraction
- Results delivery - Stability metrics with ranking
Results Format
{
"sequence_id": "variant_1",
"measurements": {
"tm_celsius": 68.5,
"tm_error": 0.5,
"tagg_celsius": 72.0,
"reversibility_percent": 85
},
"quality_metrics": {
"curve_quality": "excellent",
"cooperativity": "two-state"
}
}
Enzyme Activity Assays
Description
Measure enzymatic function including substrate turnover, catalytic efficiency, and inhibitor sensitivity.
Use Cases
- Screening enzyme variants for improved activity
- Substrate specificity profiling
- Inhibitor testing
- pH and temperature optimization
- Mechanistic studies
Assay Types
Continuous assays:
- Chromogenic substrates
- Fluorogenic substrates
- Real-time monitoring
Endpoint assays:
- HPLC quantification
- Mass spectrometry
- Colorimetric detection
Measured Parameters
Kinetic parameters:
- kcat - Turnover number (catalytic rate constant)
- KM - Michaelis constant (substrate affinity)
- kcat/KM - Catalytic efficiency
- IC50 - Inhibitor concentration for 50% inhibition
Activity metrics:
- Specific activity (units/mg protein)
- Relative activity vs. reference
- Substrate specificity profile
Workflow
- Sequence submission - Provide enzyme sequences
- Expression and purification - Optimized for activity retention
- Activity assay - Substrate turnover measurements
- Kinetic analysis - Michaelis-Menten fitting
- Results delivery - Kinetic parameters and rankings
Results Format
{
"sequence_id": "enzyme_variant_1",
"substrate": "substrate_name",
"measurements": {
"kcat_per_second": 125,
"km_micromolar": 45,
"kcat_km": 2.8,
"specific_activity": 180
},
"quality_metrics": {
"confidence": "high",
"r_squared": 0.99
},
"ranking": {
"relative_activity": 1.8,
"improvement_vs_wildtype": "80%"
}
}
Experiment Design Best Practices
Sequence Submission
- Use clear identifiers - Name sequences descriptively
- Include controls - Submit wild-type or reference sequences
- Batch similar variants - Group related sequences in single submission
- Validate sequences - Check for errors before submission
Sample Size
- Pilot studies - 5-10 sequences to test feasibility
- Library screening - 50-500 sequences for variant exploration
- Focused optimization - 10-50 sequences for fine-tuning
- Large-scale campaigns - 500+ sequences for ML-driven design
Quality Control
Adaptyv includes automated QC steps:
- Expression verification before assay
- Replicate measurements for reliability
- Positive/negative controls in each batch
- Statistical validation of results
Timeline Expectations
Standard turnaround: ~21 days from submission to results
Timeline breakdown:
- Construct generation: 3-5 days
- Expression: 5-7 days
- Purification: 2-3 days
- Assay execution: 3-5 days
- Analysis and QC: 2-3 days
Factors affecting timeline:
- Custom targets (add 1-2 weeks)
- Novel assay development (add 2-4 weeks)
- Large batch sizes (may add 1 week)
Cost Optimization
- Batch submissions - Lower per-sequence cost
- Standard targets - Catalog antigens are faster/cheaper
- Standard conditions - Custom buffers add cost
- Computational pre-filtering - Submit only promising candidates
Combining Experiment Types
For comprehensive protein characterization, combine multiple assays:
Therapeutic antibody development:
- Binding assay → Identify high-affinity binders
- Expression testing → Select manufacturable candidates
- Thermostability → Ensure formulation stability
Enzyme engineering:
- Activity assay → Screen for improved catalysis
- Expression testing → Ensure producibility
- Thermostability → Validate industrial robustness
Sequential vs. Parallel:
- Sequential - Use results from early assays to filter candidates
- Parallel - Run all assays simultaneously for faster results
Data Integration
Results integrate with computational workflows:
- Download raw data via API
- Parse results into standardized format
- Feed into ML models for next-round design
- Track experiments with metadata tags
- Visualize trends across design iterations
Support and Troubleshooting
Common issues:
- Low expression → Consider sequence optimization (see protein_optimization.md)
- Poor binding → Verify target specification and expected range
- Variable results → Check sequence quality and controls
- Incomplete data → Contact support with experiment ID
Getting help:
- Email: support@adaptyvbio.com
- Include experiment ID and specific question
- Provide context (design goals, expected results)
- Response time: <24 hours for active experiments