Sandwich ELISA development
Capture and detection antibody assessment, pair screening, standard strategy, signal-window evaluation, and condition optimization for protein biomarkers and antigens.
San Diego, California
Custom ELISA development services in San Diego
VexisBio develops and optimizes custom ELISA assays for biomarkers, antibodies, diagnostic research, and preclinical programs. We connect assay design, reagent strategy, real-matrix testing, and fit-for-purpose validation planning so the resulting data can support a clear research decision.
Custom assay development
Build an ELISA when an off-the-shelf kit is not enough
A custom assay may be the right path when a commercial kit is unavailable, existing antibodies have not been paired, the required matrix produces interference, or an early assay does not yet meet its intended sensitivity and reproducibility. We define the assay around the target, samples, decision point, and evidence required—not around a generic plate protocol.
Competitive ELISA development
Format planning for small molecules, limited-epitope targets, antibodies, or other applications where a two-site sandwich format is unsuitable.
Existing assay optimization
Troubleshooting of background, weak signal, narrow dynamic range, poor recovery, excessive variability, matrix effects, or dilution-dependent results.
Custom ELISA development capabilities
Each scope is selected according to the starting materials and intended use. A feasibility project can answer a focused technical question, while a larger program can progress through optimization and analytical performance studies.
Reagent and format strategy
- Target and epitope considerations
- Antibody-pair screening strategy
- Recombinant standard or calibrator planning
- Sandwich or competitive format selection
- Plate, blocking, detection, and substrate options
Assay optimization
- Capture and detection concentrations
- Blocking and diluent conditions
- Incubation time and temperature
- Background and nonspecific-binding control
- Standard range and sample dilution strategy
Matrix and performance studies
- Serum, plasma, CSF, supernatant, or lysate feasibility
- Spike recovery and dilutional behavior
- Precision and reproducibility planning
- Sensitivity and reportable-range assessment
- Controls and fit-for-purpose acceptance criteria
Development process
A staged path from assay concept to usable workflow
Staging the work reduces risk and makes the next investment decision explicit. The exact phases, turnaround, and acceptance criteria are defined in the project scope.
| Phase | Typical work | Decision or deliverable |
|---|---|---|
| 1. Technical review | Review target biology, intended use, reagents, sample matrix, expected range, sample volume, and performance needs. | Recommended assay format and written project scope. |
| 2. Feasibility | Assess critical reagents, signal over background, candidate antibody pairs, initial standard curve, and representative matrix behavior. | Feasibility data and a go, revise, or stop recommendation. |
| 3. Optimization | Refine reagent concentrations, buffers, timing, dilution conditions, dynamic range, controls, and plate workflow. | Draft optimized method and preliminary performance summary. |
| 4. Performance evaluation | Conduct agreed fit-for-purpose studies such as precision, recovery, dilutional linearity, sensitivity, specificity, and matrix comparison. | Method, data package, limitations, and recommended next steps. |
What we need to scope your project
- Target name, sequence, accession, or analyte description
- Species and intended research application
- Sample types and approximate sample count
- Available antibodies, standards, or existing protocol
- Expected concentration range or sensitivity goal
- Required deliverables, timeline, and downstream decision
If some details are unknown, send what is available. We can begin with a technical review and identify the most important feasibility question.
Typical project deliverables
- Project-specific development plan
- Feasibility and optimization data
- Recommended reagent and assay conditions
- Standard-curve and control strategy
- Fit-for-purpose performance summary
- Draft method or research-use protocol
- Technical report with limitations and next steps
Deliverables are matched to the contracted scope; clinical, diagnostic, GLP, or regulated validation is not implied unless specifically agreed.
Why work with VexisBio
Our San Diego team connects custom ELISA development with the upstream reagents and downstream evidence that determine whether an assay becomes useful.
Integrated reagent support
ELISA development can be coordinated with recombinant protein expression and purification, antigen strategy, standards, controls, and antibody qualification.
Biomarker-focused planning
We consider matrix effects, expected biological range, sample limitations, and the decision the biomarker data must support.
Clear technical documentation
Results are organized into a practical method and scientific narrative for internal review, partner discussion, or the next development phase.
Frequently asked questions
Custom ELISA development FAQ
When is custom ELISA development appropriate?
It is useful when no suitable commercial kit exists, available antibodies have not been paired, a target must be measured in a difficult matrix, or an existing assay needs better sensitivity, precision, recovery, or reproducibility.
Which sample matrices can be evaluated?
Projects may include serum, plasma, cerebrospinal fluid, cell-culture supernatant, tissue lysate, and other research matrices. Feasibility and sample-volume requirements are reviewed for each target and matrix.
Can you use customer-provided antibodies or standards?
Yes. A project can begin with customer-provided reagents, commercially available reagents, or a plan to develop recombinant standards and assay-ready materials. Reagent suitability is assessed during scoping and feasibility work.
Do you provide validated diagnostic tests?
VexisBio provides research-use assay development and fit-for-purpose analytical planning. Diagnostic, clinical, GLP, or regulated validation requirements must be defined and contracted separately.
Discuss your custom ELISA project
VexisBio is located in San Diego, California, and works with local and nationwide biotechnology, diagnostic, academic, and research teams. Send the target, matrix, available reagents, sample count, and intended use for an initial scope review.