Assay Development Without the CRO Overhead
Single-molecule to multiplex immunoassays
You work directly with the scientist running your assay. No project managers, no handoffs, no coordination delays.
Fog City Bio is a specialized CRO (Contract Research Organization) for immunoassay development using Simoa, HTRF, AlphaLISA, Luminex, MSD ECL, GCI, MST, and SpS.
Strict IP Confidentiality (CDA)
Based at MBC BioLabs, SF Bay Area
Assays we Develop
Custom assay development and optimization
Sandwich ELISA
Quantitative protein detection. Custom development and optimization for your matrix.
Competitive & Inhibition Assays
Small molecule, hapten, and antibody competition assays. ELISA and homogeneous formats.
Multiplex Immunoassays
Simultaneous quantitation of multiple analytes. Luminex xMAP, MSD ECL platforms.
Ultra-Sensitive Detection
Sub-picogram quantitation. Simoa, AlphaLISA, HTRF for rare biomarkers.
Binding & Kinetics Assays
Antibody affinity (KD), kinetics (kon/koff), epitope binning. Label-free methods.
Cell-Based Functional Assays
Viability, metabolism, live-cell imaging. Functional protein activity measurements.
What you get with Fog City Bio
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Direct Scientist Communication & Ownership
(Your project is led by a dedicated scientist, not a project manager.) -
Optimized Assay Performance
(Maximized S/N, wider dynamic range, and robust LoD/LoQ)
📄 See our white paper on MOA-aligned cytokine-release potency assays → -
Tailor-made Assays & Kits
(From troubleshooting and rescuing commercial ELISA kits to fully custom assay development and optimization, rather than simply running out-of-the-box protocols.)
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Rigorous Assay Characterization
(Precision, linearity, spike-recovery)
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Handoff-Ready Protocol, Data & Report
(A seamless, supported transfer of technology)
Click a thumbnail to read one of our recent White Papers.
Our 5-step rapid workflow
Step 1
10-min fit call
Define project scope, sample matrix, and target acceptance criteria.
Step 2
CDA & Materials
Execute simple CDA and coordinate shipment of samples & critical reagents.
Step 3
Rapid DoE Screen
Factorial screen to identify critical parameters (e.g., buffers, antibody concentration, incubation).
Step 4
Optimize & Finalize
Refine protocol to tighten %CV, widen dynamic range, and confirm LoD/LoQ.
Step 5
Report & Handoff
Deliver final protocol, development report, and raw data; includes a scientific debrief call.
Equipment We Use
Select the right technology for your detection requirements
Ultra-Sensitive Detection
For rare biomarkers, low-abundance proteins, and challenging matrices
→ Simoa SR-X (0.01 – 1 pg/mL)
→ AlphaLISA (0.1 – 10 pg/mL)
→ HTRF/TR-FRET (1 – 100 pg/mL)
→ Quanterix bead arrays
Multiplex Platforms
Comprehensive profiling from limited sample volumes
→ Luminex xMAP INTELLIFLEX (50-plex)
→ MSD QuickPlex ECL (10-plex)
→ Cytokine/chemokine panels
→ Custom multiplex development
Label-Free Kinetics
Real-time binding kinetics and affinity determination
→ Spectral Shift (SpS)
→ Malvern WAVEsystem (GCI)
→ NanoTemper MST
→ Epitope binning
Standard Immunoassays
Reliable, cost-effective quantitation for abundant targets
→ ELISA (colorimetric, chemilum)
→ Plate readers (Tecan, BioTek)
→ Automated liquid handling
→ High-throughput processing
Live Cell Analysis
Dynamic cellular responses and functional assays
→ Seahorse XF Pro (OCR/ECAR)
→ xCELLigence RTCA (impedance)
→ Cytation imaging
→ Metabolic profiling
Advanced Imaging
Spatial analysis and phenotypic profiling
→ Araceli Endeavor Ultra (HCS)
→ EVOS M7000 (fluorescence)
→ Refeyn TwoMP (mass photometry)
→ Confocal microscopy
Assay Customizations, Optimizations, and Development
Protocol Optimization
Optimization of antibody pairs, buffers, and incubation times to meet your target S/N, %CV, and dynamic range, whether you are starting from a commercial kit or a fully custom assay concept.
Matrix Validation
Rigorous testing in your specific sample matrix (e.g., serum, plasma, lysate). We characterize parallelism, linearity, and spike-recovery to ensure real-world accuracy.
Assay Troubleshooting & Rescue
From troubleshooting and rescuing commercial ELISA kits to fully custom assay development and optimization, rather than simply running out-of-the-box protocols. We identify failure modes and rebuild protocols that work.
Tech Transfer & Documentation
A seamless, supported transfer of technology. Fully documented, handoff-ready protocols with development reports, raw data, and training support for your team or downstream CRO.
Sample Analysis Services
Need samples run on validated methods? We process your samples using established protocols on HTRF, Luminex, MSD ECL, ELISA, GCI, MST, and SpS platforms with full documentation.
Automation-Ready Development
Protocols optimized using Opentrons Flex, Tecan Fluent, Gilson PLATEMASTER liquid handlers, and automated BioTek plate washers. Digital workflows ensure reproducible tech transfer. Delivered in machine-readable and human-readable formats.
QC snapshots
- Automation-Driven Optimization: We use Opentrons liquid handlers for key steps (e.g., titrations, sample additions) to define a robust, digital protocol.
- Minimized Process Variability: Our process removes operator "art," ensuring the protocol we develop is consistent and not dependent on a specific technician.
- Protocols Designed for Tech Transfer: We deliver a precise, machine-readable (if desired) and human-readable protocol that is built to be successfully transferred to your team or another CRO.
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Full 'Audit Trail' Documentation: You receive version-controlled protocols and complete data reports for a fully auditable "fit-for-purpose" package.
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State-of-the-Art, Maintained Equipment: Current-generation automation and plate readers. Manufacturer-warrantied, maintained on schedule, and checked with controls.
FAQs
Q: Why choose Fog City Bio over a larger CRO?
A: We are built for a different purpose. Our “micro-CRO” model provides two key advantages:
- Direct Scientist Ownership: You will not be routed through a project manager. Your single point of contact is the scientist who designs your experiment, physically runs your assay, analyzes your data, and writes your final report.
- Lean, Cost-Effective Operations: We focus exclusively on rapid protocol optimization. We don’t have the massive overhead of a full-service, GLP-compliant facility. Our “GLP-lite” rigor and automation-driven processes deliver a high quality, “fit-for-purpose” data package, and we pass those significant overhead savings directly to you.
Q: Is Fog City Bio GLP/GMP?
We operate RUO‑only with GLP‑lite QC for R&D decision‑making. For regulated studies, we provide technology transfer documentation and support back to your GLP/GMP labs.
Q: How fast is the turnaround?
We propose a timeline during the fit call; simple tune‑ups often begin within days of material receipt.
Q: How does Fog City Bio protect IP?
A comprehensive mutual CDA available. We follow strict sample handling and data privacy practices; only assigned scientists access your data. We anonymize samples through our internal tracking system.
Q: What kind of ELISAs does Fog City Bio offer?
Direct, Indirect, Competitive, Sandwich, ELISpot.
Q: What kind of assays does Fog City Bio offer?
Cell based assays, Grating-Coupled Interferometry (GCI), Microscale Thermophoresis (MST), Spectral Shift (SpS), affinity & potency.
Q: What kind of reporter proteins does Fog City Bio use?
Colorimetric, fluorescent, luminescent, FRET/HTRF.
Q: What kind of cell lines does Fog City Bio work with?
Commercially-available primary cells and immortalized mammalian cells: both adherent and suspension.
Q: What do you need from us to get started?
- Samples
- Antibodies / detection reagents
- Prior data (if any)
- Desired detection range
- Matrix info
Q: What does a typical project with Fog City Bio look like?
A simple 4-5 step workflow:
Consult → intake → design → run → deliverable.
Q: How do you price projects?
Standard ELISA work: Standard samples run on an existing ELISA kit can start as low as $1,000 per run, with an additional $200 per plate.
ELISA Creation and Development Work: Pilot runs (assay creation and development pilots) start at $1,800 and decrease marginal cost depending on volume and number of runs. This cost considers the additional time required for custom projects when planning, analyzing, and reporting.
Additional services:
- SPR pricing is highly variable, depending on the kinetics of the molecules, chemistry of the chips used, and assay requirements. Fast-kinetics assays (less than 1 hour per sample) start at $1,800 per run, while slow interactions can cost up to twice as much.
- Cell based assays are too variable to summarize, please set up a meeting for us to discuss! The lowest cost to expect will be an additional $1,000 but this will typically add $6,000 to any project, but it can be much lower depending on assay requirements and cell line.
- Gel/Blot based assays are $700 per gel or $800 blot. More for atypical or custom assay designs (~$1,200).
- Other plate-based assays are comparable to ELISA pilot runs (~$1,800).
Additional Fees: Our set-up fee for new projects is typically $1,000. This includes client on-boarding, technology and data transfer, sample ingestion, and overall project management. This can go as low as $400 for particularly straightforward projects. Passthrough pricing is the most typical arrangement for materials cost, where we will purchase the reagents required, to be reimbursed by the clients at project termination. Development reports are often included for basic projects. All of your raw and analyzed data, the final developed protocol(s), and a smile are always offered for free.
Book a 15-Minute Consult
We typically estimate about 15 minutes for introductory calls but set aside 30 minutes to ensure ample time to discuss all your needs.
All consultations are confidential and commitment-free.
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Quick Intake
Too busy or too shy for a meeting?
Drop a question and we’ll get back to you.
RUO only. No diagnostic claims. Confidential by default; mutual CDA available.
Prefer to skim first? Read our white paper →