Custom Cell Line, Assay, and Protein Development Capabilities

Your Target Biology, Our Expertise - Building a Better Product Together

Cell-based assays are valuable tools throughout the drug discovery and development process. However, in-house or home brew cell line, assay, or protein development can be difficult and expensive, requiring months to develop, tying up valuable internal resources, and can be technically challenging, further straining resources and timelines.


When an off-the-shelf option is not available, trust Eurofins DiscoverX custom development program to create cell line, assay, and protein solutions that will deliver the quality results you expect. We offer a wide range of custom services to support drug development programs from discovery through QC lot release.


The Eurofins DiscoverX custom development program delivers tailor-made proteins, cell lines, and assays optimized for your requirements. This program enables you to jump-start your drug discovery and development initiatives by solving your development challenges, while saving you time, money, and resources. Leverage over 20 years of custom development expertise and work with us as we have with hundreds of drug discovery programs at multiple companies globally to enable programs through screening, lead optimization, characterization, and bioanalytical assay development.

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Custom Assay Development


  • Development Expertise – Decades of cell-based assay development, cell line engineering, and recombinant enzyme development expertise
  • Cell Line Engineering Capability - Exogenous expression approaches (constitutive vs inducible) or gene editing (e.g. KO/KI with CRISPR/Cas9)
  • Collaborative - Consultative product development with regular updates through a dedicated project manager
  • Complete Solution – Customized assay development with screening and profiling services within the same team


With a history of developing hundreds of customized assays for drug discovery programs at multiple companies globally through screening, lead optimization, and bioanalytical assay development, you can work confidently knowing you are working with a group understanding what you need to move your therapeutic forward.

Contact Custom Dev

The Eurofins DiscoverX CAD program offers cell line and assay development expertise for multiple targets, applications, and technologies.

Multiple Targets and Applications

  • ​Immuno-Oncology Targets – Build neutralizing antibody, potency, cytotoxicity, signaling, or reporter gene assays for immune relevant receptors; and focus on application for ADCC, CDC, ADCP, T cell redirection, and more (learn more)
  • GPCR Targets – Develop orthologs and various assays forβ-arresitn recruitment, cAMP accumulation, calcium flux, or pharmacotrafficking for orphan or other GPCRs (learn more)
  • Compound-Target Engagement Assays – Generate InCELL Hunter™ or InCELL Pulse™ binding assays and focus on unusual "undruggable" targets (learn more)
  • Novel Pathway Assays – Create signaling (e.g. SH2 recruitment), translocation (e.g. internalization), reporter gene, and more assay types

Technologies and Capabilities

  • ​Custom bioassay development and qualification
  • MOA-reflective, Enzyme Fragment Complementation (EFC) cell-based, functional and binding assays
  • Protein-protein interaction, enzymatic, and other assay types
  • Cell-line engineering with CRISPR / Cas9 including knock-outs and knock-ins

CAD Program Process

Phase 1: Project Definition

  • In-Depth Consultation – Discussion with CAD team about project goals and scope
  • Extensive Research – CAD team investigates and evaluates project feasibility
  • Deliverables – Detailed work plan with timelines, project deliverables, and pricing

Phase 2: Project Execution

  • Additional Materials – Project manager obtains any necessary materials
  • Assay Development – Stable cell line development, functional testing with molecules, stability testing of clones, assay development and optimization
  • Deliverables – Bi-weekly status updates, detailed milestone reports, and access to our scientific staff for continuous progress reports

Phase 3: Material Delivery

  • Deliverable – Qualified, stable cell line or assay based on the work plan, including a detailed assay protocol
  • Additional Options – Screening and profiling of client’s molecules

PathHunter® Cell-Based Assay Development Services

PathHunter is a versatile cell-based assay platform, based on our proprietary EFC technology, successfully employed to develop validated assay solutions for over 700 targets spanning many target classes including GPCRs, Kinase, Checkpoint Modulators, NHRs, and more. Innovative applications of this core technology has enabled the development of robust, reliable, and high-throughput-friendly chemiluminescent assays to measure protein- interaction, protein translocation, secretion, and degradation, and receptor dimerization.


Path-Hunter cell-based technology format can query many types of interactions

  • Measure inducible and constitutive protein interactions
  • Measure protein translocation to various intracellular locations in a non-imaging HTS friendly assay
  • Accurately measure protein levels and stabilization


InCELL Cell-Based Assays for Intracellular Target Binding

Universal Cell-Based Compound-Target Binding Assays

InCELL Pulse and InCELL Hunter are novel, yet powerful in vitro cellular ligand binding assay platforms that can be used to determine compound binding in a native cellular environment. Both platforms use enzyme fragment complementation technology to measure binding to the protein of interest and are powerful development tools to evaluate target engagement for intractable targets where other technologies have been unsuccessful.


InCELL - A simple cell-based assay for complex targets

  • Cell-based assau broadly applicable to several target classes
  • Target-specific response
  • Direct measure of intracellular binding to target
  • activity independent
  • HTS compatible
  • Bridge between in vitro binding assay and cellular functional assay

How it Works


Engineered Cell Lines

A flexible approach to customized cell line generation
Using proprietary Eurofins DiscoverX vectors and viral transduction techniques, we can build custom engineered cell lines specific to your project requirements including generating cell lines with mutations, of different species (orthologs), or modifying cell backgrounds for an existing catalog product.


  • Cell background variants
  • Mutant or orthologs of existing catalog products
  • Protein overexpression
  • Bulk cell-scale up

Custom PathHunter® Assay Development Solutions

Comprehensive flexible cell-based assay solutions
When you need more than just a cell line, you can count on our custom assay development team to develop and validate a comprehensive assay solution. Our team of research scientists will work closely with you to determine project scope, feasibility, time-lines and budget to develop a workplan that meets your needs.

Flexible Partnership and Development Options

  • Low up-front cost
  • Routine updates
  • Flexible business models: fee-for-service, milestone driven and more


InCELL Assay Development Solutions

Intracellular Binding Assays - measure cellular potencies for your compounds
We can build custom engineered cell lines specific to your project requirements in as little as 6-8 weeks using the InCELL technology platform.


  • Intractable targets
  • Cell background variants
  • Mutant or orthologs of existing catalog products
  • Bulk cell-scale up


HitHunter® Biochemical Assay Development Services

The HitHunter Assay is a validated platform for biochemical quantification of second messenger signaling for cAMP and cGMP. Extension of the HitHunter principle to novel targets allows for investigation of protease and substrate activity. HitHunter assays are formatted as competitive immunoassays, where analytes are detected in solution, without separation or wash steps, providing improved sensitivity and precision compared to conventional immunoassays.


HitHunter Biochemical Assay Development Services will work closely with you to develop a custom assay to detect protease and substrate activity or measure an analyte, providing comprehensive solutions where you need them most.

HitHunter biochemical technology has many advantages:

  • Develop novel assays for identifying analytes
  • Develop cleavage assays to test protease activity
  • Develop assays for use with primary cells
  • All assays will be HTS compatible, adaptable to 1536 applications
  • Chemiluminescent detection - minimizes false positives from auto fluorescence
  • Reliable and robust assay with high Z' (0.75) HTS-friendly
  • Large assay windows
  • Broad application to multiple target classes

How it Works


Custom HitHunter™ Assay Development Solutions

An award winning, homogenous assay platform for precise, sensitive analyte detection
Using proprietary DiscoverX technology, we can generate custom protease cleavage assays that utilize ED conjugated to the protease specific cleavage sequences as a substrate proteases.


  • Monitoring Gi and Gs targets
  • Identifying agonist, antagonist, allosteric, partial agonists and inverse agonists
  • High-throughput screening (HTS & uHTS) campaigns
  • Ligand profiling
  • Use with primary cells, orphans, frozen and membrane
  • Identifying PDE inhibitors

Accelerate your drug discovery project with custom enzymes tailored to your needs.


When an off-the-shelf enzyme is not available or when your research depends on specialized or challenging enzymes, Eurofins DiscoverX’s Custom Enzyme Development (CED) service can fulfill your needs. With over 25 years of enzyme development experiences, our dedicated experts from the orignal Millipore/ Upstate kinase enzyme development team will deliver high-quality enzymes at the specification required to meet your research goals. Whether it is developing an enzyme from scratch or customzing one from our available catalog, our team will work closely with you to create a cost-effective solution designed to fulfil your requirements.


Quality is our focus when developing enzymes to ensure the highest purity (>95%), specific activity, and lot-to-lot consistency. A detailed certification of analysis indicating batch-specific product performance in terms of purity and catalytic activity will be provided. During product development, our QC validation goes beyond specific activity determination, routinely including Km substrate and Km ATP determinations in addition to Z’ studies and inhibitor response assays.

Custom Enzyme Development Process

Phase 1: Project Definition

  • In-Depth Consultation – Discussion with CED team about project goals and scope
  • Extensive Research – CED team investigates and evaluates project feasibility through extensive background research including literature surveys and protein database interrogations
  • Deliverables – Detailed work plan with timelines, project deliverables, and pricing

Phase 2: Project Execution

  • Materials Preparation – Project manager obtains all necessary materials
  • Enzyme Development and Analysis – Production process development, full-scale production in various expression systems (insect, bacterial, or mammalian), and final product analysis (SDS-PAGE, Western blot, TSA (thermal shift assay), analytical SEC (size exclusion chromatography), mass spectrometry, and enzyme assay)
  • Deliverables – Status updates, detailed milestone reports, and access to our scientific team for continuous support

Phase 3: Material Delivery

  • Deliverable – High-quality proteins and detailed result reports
  • Additional Options – In-house screening and profiling services upon request