Immunoassay Development & Validation
SRID Assay Development and Validation for Vaccine Antigen Quantification
Develop and qualify single radial immunodiffusion (SRID) assays for the accurate, precise, and reproducible quantification of recombinant protein antigens in vaccine candidates. Our service supports vaccine developers and biotech companies in preclinical and clinical stages, particularly those working on recombinant protein vaccines, by providing method development and full validation to ensure regulatory-compliant quality control.
What Is SRID Assay Development?
Single radial immunodiffusion (SRID) is an agar gel precipitation test used to determine the quantity or concentration of an antigen in a sample. It has been the accepted method for determining the potency of inactivated influenza vaccines since 1978, and remains the compendial standard for antigen potency and stability testing of protein-based vaccines.
Our SRID assay development and validation service is designed for vaccine developers who need robust, regulatory-compliant immunoassays to quantify specific antigens in their vaccine candidates. We develop and validate SRID assays that ensure accuracy, precision, and reproducibility, providing the confidence needed for quality control and regulatory submissions.
The service is particularly suited for recombinant protein vaccines, where precise antigen quantification is critical for batch consistency and product characterization. By establishing a validated SRID method, we help you demonstrate that your vaccine candidate consistently contains the intended antigen content.
Regulatory Acceptance
SRID is a well-established method accepted by regulatory authorities for vaccine potency testing, providing a recognized path for quality control.
- Accepted method for influenza vaccine potency since 1978
- Compendial standard for protein-based vaccine antigen testing
- Recognized by regulatory agencies for vaccine quality control
Precise Antigen Quantification
The assay provides quantitative determination of specific antigens, enabling accurate measurement of protein content in vaccine candidates.
- Quantitative measurement of antigen concentration
- Designed for accuracy, precision, and reproducibility
- Supports batch-to-batch consistency assessment
From Preclinical to Clinical
Our service supports vaccine developers at various stages, providing validated methods for product characterization and quality control.
- Suitable for preclinical and clinical stage programs
- Supports recombinant protein vaccine development
- Provides documentation for regulatory submissions
Why SRID for Vaccine Quality Control?
SRID assays are a key immunochemistry method used for vaccine quality control, ensuring accurate protein quantification and consistency in vaccine production. The method's longevity and continued use in regulatory settings reflect its reliability and the confidence regulators place in its results.
Clinical evidence has indicated the relevance of SRID as a potency assay, and its unique features are likely responsible for its continued use even as newer technologies have emerged. For vaccine developers, using a compendial method can simplify regulatory discussions and provide a clear path for product approval.
| Feature | SRID Assay | Relevance to Vaccine QC | Regulatory Context |
|---|---|---|---|
| Method Maturity | Accepted since 1978 | Proven track record in vaccine potency testing | Compendial standard for protein vaccines |
| Quantitative Output | Antigen concentration measurement | Enables batch consistency assessment | Supports release testing requirements |
| Specificity | Antigen-specific detection | Measures target antigen without cross-reactivity | Supports product characterization |
| Reproducibility | Validated precision | Ensures consistent results across runs | Meets regulatory expectations for assay performance |
Our SRID Assay Development Workflow
We follow a systematic approach to develop and validate SRID assays tailored to your specific vaccine candidate. Our process is designed to deliver a robust, regulatory-compliant method that meets your quality control needs.
Method Development
We develop the SRID assay for your specific antigen, optimizing conditions for antigen-antibody precipitation and establishing the assay protocol. This includes selecting appropriate reagents and defining assay parameters.
Assay Optimization
We refine the assay conditions to ensure optimal performance, including antibody concentration, gel composition, and incubation conditions. The goal is to achieve a sensitive and specific assay for your antigen.
Validation Studies
We conduct validation studies to demonstrate the assay's accuracy, precision, specificity, and reproducibility. This includes assessing robustness and defining the assay's detection range.
Documentation and Transfer
We provide comprehensive documentation of the method development and validation, including protocols, validation reports, and standard operating procedures. This documentation supports regulatory submissions and technology transfer.
Customization and Assay Features
Every vaccine candidate is unique, and your SRID assay should be too. We customize the assay development to your specific antigen and quality control requirements.
Our approach ensures that the final assay is fit for its intended purpose, whether for release testing, stability studies, or product characterization.
Tailored to Your Antigen
The assay is developed specifically for your recombinant protein antigen, ensuring relevant and reliable quantification.
- Custom assay design for your target antigen
- Optimized for your vaccine candidate
- Designed to meet your QC requirements
Validation to Standards
Validation studies are designed to meet regulatory expectations for assay performance and documentation.
- Validation of accuracy, precision, and reproducibility
- Robustness assessment
- Documentation for regulatory submissions
Quality Control Support
The validated assay supports your quality control program, enabling consistent product release and stability testing.
- Supports batch release testing
- Enables stability studies
- Provides data for product consistency
Validation Parameters and Deliverables
Our validation studies are designed to demonstrate that the SRID assay is suitable for its intended purpose. We assess key performance characteristics and provide comprehensive documentation.
The deliverables from our service provide everything you need to implement the assay in your quality control program and support regulatory submissions.
| Parameter | Assessment | Deliverable | Regulatory Relevance |
|---|---|---|---|
| Accuracy | Recovery of known antigen concentrations | Validation report with accuracy data | Demonstrates assay measures the correct amount |
| Precision | Repeatability and intermediate precision | Precision data and statistical analysis | Ensures consistent results across runs |
| Specificity | No cross-reactivity with other components | Specificity assessment data | Confirms assay measures the target antigen |
| Robustness | Assay performance under varied conditions | Robustness evaluation report | Demonstrates assay reliability |
Applications Across Vaccine Development
SRID assays serve multiple purposes throughout vaccine development, from early characterization to late-stage quality control. Our service supports these diverse applications.
By providing a validated SRID method, we help you generate reliable data for decision-making and regulatory interactions.
Batch Release
Use the validated SRID assay for routine release testing of vaccine batches, ensuring each batch meets specifications.
- Quantitative antigen measurement for release
- Supports batch-to-batch consistency
- Provides data for lot release documentation
Stability Monitoring
Monitor antigen content over time to assess vaccine stability and support shelf-life determination.
- Track antigen potency during storage
- Support stability study programs
- Generate data for shelf-life claims
Product Characterization
Characterize your vaccine candidate's antigen content as part of product development and characterization studies.
- Quantify antigen in development batches
- Support formulation development
- Provide data for regulatory submissions
Comparison with Alternative Assay Platforms
While several assay platforms can quantify antigens, SRID offers unique advantages for vaccine quality control. Understanding these differences helps you select the right approach for your program.
The choice of assay platform depends on your specific needs, including regulatory requirements, throughput, and the nature of your antigen.
| Platform | Key Features | Considerations | Typical Use |
|---|---|---|---|
| SRID | Compendial standard, quantitative, no specialized equipment | Lower throughput, requires specific antibodies | Vaccine potency and stability testing |
| ELISA | High throughput, sensitive, widely used | May require assay development, potential for matrix effects | High-throughput antigen quantification |
| Surface Plasmon Resonance (SPR) | Label-free, real-time binding analysis | Requires specialized equipment, may need assay development | Binding studies and kinetic analysis |
| Turbidimetric Immunoassays | Automated, quantitative | May require specific reagents, platform-dependent | Automated antigen quantification |
Regulatory Considerations
Regulatory compliance is a critical consideration in vaccine development. SRID assays are recognized by regulatory authorities, providing a well-understood path for quality control.
Our service is designed to generate the documentation and data needed to support your regulatory submissions, whether for clinical trial applications or marketing authorization.
Why Choose Our SRID Assay Service
Our service combines deep expertise in immunochemistry with a focus on regulatory compliance. We understand the specific challenges of vaccine development and provide assays that meet your quality control needs.
We work closely with you to understand your antigen and quality control requirements, developing a validated SRID assay that you can rely on.
FAQ
What is the SRID assay used for in vaccine development?
SRID is used for the quantitative determination of antigens in vaccine candidates, serving as a key quality control method. It is the accepted method for determining the potency of inactivated influenza vaccines and is a compendial standard for protein-based vaccines, ensuring accurate protein quantification and consistency in vaccine production.
How is the SRID assay validated?
Validation studies assess accuracy, precision, specificity, and reproducibility of the assay. We evaluate the assay's performance characteristics, including robustness and detection range, and provide comprehensive documentation of the validation results to support regulatory submissions.
Can the SRID assay be used for recombinant protein vaccines?
Yes, SRID assays are suitable for quantifying recombinant protein antigens in vaccine candidates. The assay is developed specifically for your antigen, ensuring relevant and reliable quantification for quality control purposes.
What documentation is provided with the service?
We provide comprehensive documentation including assay protocols, validation reports, and standard operating procedures. This documentation supports regulatory submissions and technology transfer to your quality control laboratory.
References
- Nakhanova G, Chervyakova O, Shorayeva K. Single Radial Immunodiffusion (SRID) Assay for Quantitative Determination of Recombinant SOD Protein in a Brucellosis Vaccine Candidate: Method Development and Validation. Methods Protoc 2026 Jul 28. View on PubMed
- Utilisation of monoclonal antibodies in the single radial immunodiffusion .. The single radial immunodiffusion (SRID) assay is currently the compendial standard for determining the antigen potency and stability of protein ... View article
Develop a Validated SRID Assay for Your Vaccine Candidate
Contact us to discuss your SRID assay development and validation needs. Our team can help you establish a robust, regulatory-compliant method for antigen quantification in your vaccine program.