Custom Immunoassay Design & Validation
Bespoke Immunoassay Development for Non-Standard Biologics and Vaccine Antigens
Many biologics require bespoke assays for unique antigens. Our custom immunoassay design service develops and validates detection methods tailored to your specific target protein, overcoming challenges with non-standard analytes. From antibody screening to fully validated and manufactured assay kits, we support biotech and pharma R&D teams working on novel biomarkers, vaccine candidates, and quality control applications. Immunoassays are widely used for the determination of various analytes in disease diagnosis, food safety, and environmental monitoring, and custom development extends this proven technology to novel targets.
What Is Custom Immunoassay Design?
Custom immunoassay design is the process of developing a detection method built around a specific analyte—typically a protein, peptide, or small molecule—for which no commercial assay exists. Immunoassays depend on an antibody's natural ability to bind to a distinct epitope on the target, and the assay format is engineered to translate that binding event into a measurable, quantitative signal. For biologics with non-standard antigens, a bespoke approach is often the only path to reliable quantification.
The service covers the full development arc: screening antibody panels or matched pairs, selecting the optimal assay format, optimizing conditions, and validating performance parameters such as sensitivity, specificity, and reproducibility. The end point is a fully validated assay that can be manufactured consistently for ongoing use—whether in vaccine quality control, biomarker studies, or lot-release testing.
Immunoassays are widely used for the determination of various analytes in disease diagnosis, food safety, and environmental monitoring. Custom development extends this proven technology to novel targets, enabling R&D teams to generate the quantitative data their programs require.
Non-Standard Analytes
Designed for unique target proteins, vaccine antigens, and novel biomarkers where off-the-shelf kits are unavailable.
- Recombinant proteins and vaccine candidates
- Novel biomarkers without commercial reagents
- Analytes in complex matrices
Multiple Assay Formats
Choose the detection platform that fits your sensitivity needs and throughput requirements.
- ELISA and plate-based formats
- Multiplex MILLIPLEX assays
- Ultrasensitive single-molecule counting
QC-Ready Output
Assays are developed with quality control in mind, supporting vaccine consistency and lot-release testing.
- Quantitative determination of target protein
- Documented validation parameters
- Manufactured for consistent supply
Why Custom Assay Development Matters
Standard commercial assay kits cover only a fraction of the analytes that matter in modern biologics development. When your target is a novel vaccine antigen, a recombinant protein with post-translational modifications, or a biomarker with no existing reagent pair, you cannot rely on catalog products. A custom assay bridges that gap, turning a unique target into a quantifiable, quality-controlled measurement.
For vaccine programs, accurate protein quantification is essential to ensure consistency in production. A well-designed immunoassay provides the data needed to confirm that each lot contains the expected amount of antigen, supporting regulatory submissions and release testing. The same rigor applies to biomarker studies, where reproducible detection underpins every downstream decision.
| Challenge | Off-the-Shelf Kit | Custom Assay | Impact |
|---|---|---|---|
| Novel antigen | No reagent available | Antibody screening and matched-pair selection | Enables quantification from day one |
| Complex matrix | Cross-reactivity risk | Matrix-specific optimization | Cleaner signal, fewer false results |
| Sensitivity needs | Fixed detection limit | Format selection (ELISA, multiplex, ultrasensitive) | Detection limit matched to your analyte |
| QC / lot release | Not designed for your product | Validation with documented parameters | Defensible data for release testing |
How Custom Assay Development Works
Our custom assay development process is structured to move your target from concept to a validated, manufacturable assay. Each project is tailored to the analyte, the sample matrix, and the intended use—whether research, quality control, or clinical application.
Project Scoping and Feasibility
We begin by understanding your target protein, its source, the sample matrix, and the intended assay application. This includes reviewing available reagents—such as existing antibodies or recombinant standards—and defining the performance requirements the assay must meet, including sensitivity and specificity targets.
Antibody Screening and Pair Selection
For targets without a proven reagent pair, we screen antibody panels to identify candidates with the right affinity and specificity. The goal is to select a matched pair that recognizes distinct epitopes, enabling a sandwich format with minimal cross-reactivity and a clean signal-to-noise profile.
Assay Format and Condition Optimization
We select the optimal format—ELISA, multiplex, or ultrasensitive detection—and optimize key parameters including coating concentrations, blocking conditions, incubation times, and detection reagents. The assay is refined to deliver reproducible results across the expected dynamic range of your analyte.
Validation and Manufacturing Transfer
The optimized assay undergoes validation to document performance characteristics such as sensitivity, specificity, precision, and recovery. Once validated, the assay can be manufactured consistently, providing a reliable supply of kits or plates for ongoing quality control and research use.
Customization Options
Every custom assay project is unique, and the level of customization can be tailored to your program's stage and goals. From a single validated assay for internal use to a manufactured kit for broader distribution, we adapt the scope to your needs.
Antibody Panel Screening
When no validated antibody pair exists for your target, we screen available panels to identify suitable candidates.
- Screening of antibody panels or matched pairs
- Selection based on affinity and specificity
- Reduces cross-reactivity risk
Platform Flexibility
Choose the detection platform that matches your sensitivity and throughput requirements.
- ELISA for standard throughput
- Multiplex for multi-analyte panels
- Ultrasensitive SMC for low-abundance targets
Validation Documentation
Validation can be scoped to your needs, from basic performance checks to comprehensive documentation for QC release.
- Sensitivity and specificity assessment
- Precision and recovery studies
- Documentation for quality control use
Applications Across the Biologics Lifecycle
Custom immunoassays support biologics programs at multiple stages, from early research through manufacturing quality control. The same core technology—antibody-based detection—is adapted to different questions and decision points.
| Application | Typical Target | Assay Goal | Key Output |
|---|---|---|---|
| Vaccine quality control | Recombinant antigen (e.g., SOD protein) | Quantitative determination of antigen content | Lot-release data, consistency monitoring |
| Biomarker research | Novel protein biomarker | Reproducible detection in study samples | Quantitative data for research decisions |
| Process development | Product-related impurities | Monitoring during upstream/downstream processing | Process control data |
| Stability studies | Active pharmaceutical ingredient | Tracking antigen integrity over time | Stability profile for shelf-life decisions |
Assay Formats We Develop
The choice of assay format depends on your analyte's abundance, the sample matrix, and the sensitivity required. We develop assays across the major immunoassay platforms, selecting the format that best fits your data needs.
| Format | Best For | Typical Sensitivity | Throughput |
|---|---|---|---|
| ELISA | Standard protein quantification | pg/mL to ng/mL range | 96-well plate format |
| Multiplex (MILLIPLEX) | Multi-analyte panels | pg/mL range per analyte | Multiple analytes per well |
| Ultrasensitive (SMC) | Low-abundance targets | Sub-pg/mL detection | Single-analyte, high sensitivity |
| Single Radial Immunodiffusion | Vaccine antigen quantification | µg/mL range | Simple, plate-based readout |
Quality and Documentation
A custom assay is only valuable if its results are trustworthy. Our development process emphasizes documentation at every stage, so you have the data needed to defend your results—whether in a research report, a regulatory submission, or a quality control release.
Performance Characterization
Assays are characterized for key performance parameters, providing confidence in the data they generate.
- Sensitivity and detection limit
- Specificity and cross-reactivity assessment
- Precision and reproducibility
Comprehensive Records
Development and validation activities are documented, giving you a clear record of how the assay was built and verified.
- Protocol records
- Validation reports
- Batch records for manufactured kits
Consistent Supply
Validated assays can be manufactured to provide a consistent supply of kits for ongoing use.
- Reproducible kit production
- Quality control on manufactured lots
- Supply for research or QC programs
Getting Started
Starting a custom assay project begins with a conversation about your target and your goals. We'll discuss the analyte, the sample matrix, the intended application, and the performance requirements—then propose a development plan tailored to your program.
Why Choose Custom Assay Development
When your target is unique, a custom assay is not a luxury—it's a necessity. Off-the-shelf kits simply cannot measure what they were not designed to detect. Custom development turns your novel antigen into a quantifiable, quality-controlled measurement, enabling the data your program needs.
The value extends beyond the assay itself. A well-designed, validated assay becomes a reusable asset—supporting research, process development, and quality control across the product lifecycle. The upfront investment in development pays dividends in data quality and consistency.
FAQ
What types of targets can a custom immunoassay be developed for?
Custom immunoassays can be developed for a wide range of analytes, including recombinant proteins, vaccine antigens, novel biomarkers, and small molecules. The key requirement is that the target is immunogenic—meaning antibodies can be raised against it—and that a suitable antibody pair can be identified or developed. For non-standard analytes where no commercial reagents exist, antibody screening is typically the first step.
How is a custom assay validated?
Validation typically includes assessment of sensitivity (detection limit), specificity (cross-reactivity with related molecules), precision (repeatability and reproducibility), and recovery (accuracy in the intended matrix). The depth of validation can be scoped to your needs—from basic performance checks for research use to comprehensive documentation for quality control and release testing.
What information do you need to start a custom assay project?
To scope a project, we need information about your target protein (sequence, source, purity), the sample matrix (buffer, serum, culture supernatant), the intended application (research, QC, release testing), and any existing reagents you have. This context allows us to propose a development plan and estimate the key steps involved.
Can the assay be manufactured for ongoing use after development?
Yes. Once an assay is developed and validated, it can be manufactured to provide a consistent supply of kits or plates for ongoing use. This is particularly valuable for quality control applications, where the same assay must be used repeatedly across production lots to ensure consistency.
Discuss Your Custom Assay Project
Tell us about your target protein and application. We'll help you determine the right assay format and development approach for your program.