Functional Bioassays

Bioassays for Application within Preclinical and Clinical Studies

FyoniBio has long-term expertise in the development of functional and potency bioassays for different biotherapeutics (e.g., antibodies and glycoproteins). In addition to non-cellular formats, our team is also used to work with a number of complex cell-based assays using different target and effector cells including human primary immune cells. The portfolio comprises methods to assess target and effector cell binding, signaling events, viability, cytotoxicity, cytokine release and other immune functions. We offer custom-specific assay development and validation for application within preclinical and clinical studies.

The comprehensive assay portfolio covers various types of biotherapeutics from small oligonucleotides to large proteins like antibodies and multiple indications, e.g., oncology, rheumatology, immunology and immuno-oncology, hematology, enzyme replacement, and endocrinology.

Overview of Available Bioassays

Binding Assays

  • Target binding
  • Fc receptor binding
  • Dual cell binding
  • Blood cell binding
  • Antigen quantification
  • Binding kinetics (affinity)
Binding of a test antibody to different target cell lines

Cell Viability and Cytotoxicity Assays

  • Viability
  • Proliferation assays
    (2D or 3D culture)
  • Apoptosis detection
  • ADCC with different effector cells
  • CDC
  • Phagocytosis
  • Cell cycle analysis
  • nAb assay
dose-dependent cytotoxicity curves of test and reference antibody
ADCC activity of a defucosylated compared to a reference antibody

Immuno-Oncology Assays

  • Isolation, differentiation and phenotyping of immune cell populations
  • T cell activation
  • T cell proliferation
  • Immune checkpoint assays
  • Mixed lymphocyte reactions
  • Cytokine release
IL-2 secretion in an allogeneic mixed lymphocyte reaction

Signaling Assays

  • Receptor modulation
  • Receptor phosphorylation
  • Signal transduction
  • Reporter gene activity
  • cAMP release assay
  • Biomarker


  • Protein or cell activation
  • Internalization
  • Cell Adhesion 
  • Migration 
  • Coagulation assays for blood factors
  • Enzymatic activity assays
  • Drug combination
  • Custom-specific assay development

What conclusions can be drawn from a bioassay?

Bioassays are used to measure the biological activity and effects of a compound. They can be used to monitor quality, functionality and safety of the compound.

Cell-based assays are in vitro experimental tools using viable cells to analyze the efficacy of compounds in a biological environment. Those complex approaches are considered more physiologically relevant than standard plate-based immunoassays, because they better mimic the in vivo situation by employing proteins in their biologic conformation, resembling a multi-cellular environment, allowing interaction within the cellular network, and using downstream readouts which reflect the signal transduction. Cell-based assays are particularly important for multi-functional proteins.

Cell-based Assays

In order to support our bioassay portfolio with a wide spectrum of cell types from different origin and histology, we run a mammalian cell culture facility with the following capabilities:

  • cell culture of immortalized cells (cell lines)
  • isolation, differentiation and cultivation of primary cells
  • 3D spheroid cell models
  • generation of stably transfected cell lines, e.g., for disease models or effector cells
  • maintenance of frozen cell culture stocks

We have more than 130 different human cell lines and cell lines from several animal species available for the use in cellular bioassays. Cell lines could also be provided by the customer, if an appropriate cell line was already selected or a custom-assay should be transferred to our testing facility.

Overview of cell lines per tissue type available for bioassay develoment and analysis at FyoniBio

Which platforms and technologies do we use?

FyoniBio offers a wide range of innovative platforms and technologies which can be applied in functional testing, such as ELISA/ ECLIA, flow cytometry, alphaScreen®, Switchsense or RT-PCR.


Bioassay Flyer

Dr. Doreen Weigelt