Cell Based Assays

The development of protein-based therapeutics requires comprehensive product analysis. Complete characterization calls for the use of distinct and complementary methods, including structural and physicochemical analysis, binding assays, and cell-based bioassays.

Sartorius has developed a range of platforms to analyze the function of protein-based therapeutics. We offer ready-to-use and customizable cell-based assays, allowing you to save time while still fully characterizing your molecule’s biological activity and potency. Our platforms measure your molecule’s effector functions, induction or inhibition of secondary and tertiary activities (including immune interactions), and antibody internalization.  

Our off-the-shelf bioassays are fully GCP, GLP, and GMP compliant, delivering cost-effective testing services that accelerate biopharmaceutical development.

Fc binding expertise

Our bioassay portfolio includes antibody-dependent cellular cytotoxicity (ADCC) with multiple effector types, antibody-dependent cellular phagocytosis (ADCP), and complement-dependent cytotoxicity (CDC).  Evaluating the ability of your biologic to activate these pathways is a critical step in the development and characterization of therapeutic antibodies

We also offer a range of Fc receptor binding assays to complement our Fc function analysis platforms

Ready-to-use assays and platforms

For standard molecules, our ready-to-run assays save the time and expense of starting from scratch, accelerating your characterization and development

For more complex assays, our platforms can provide a springboard for analytical development

Lot release

Full cGMP capability at our global sites, coupled with our expertise in robust assay development, allows us to move your selected assays from characterization to lot release qualification and validation with ease

Single-source characterization

Sartorius offers a complete suite of assays to characterize antibody drugs along the entire development pipeline. This makes it possible to link a protein’s structural and physicochemical properties with its biological function, facilitating decision-making

Find Your Bioassay

Cell Based Bioassay

Fc Function Characterization

Custom potency assays


Immune cell assays

Lymphoid-enriched ADCC

ADCC assays

NK cell ADCC

Cell based binding assays 

Reporter assay ADCC



Potency assays are a quantitative measure of biological activity and a critical component of drug development. They support stability studies and lot release applications throughout the development process, from discovery to clinical manufacturing and commercialization.

Regulatory-Ready Bioanalytical Services

Sartorius offers development services for standard and custom potency assays. Off-the-shelf assays can be optimized to meet a drug developer’s needs, or assays can be custom-designed and developed for optimized results. Fully qualified or validated assays can be transferred to our customers for routine testing and monitoring.

Our potency assays are designed and performed in accordance with all applicable regulatory requirements, including USP1033, European Pharmacopoeia, and ICH Q2B.

We also offer assay development to support comparability studies and perform evaluations of process changes, including:

  • Custom assay development to measure neutralization
  • Cell proliferation and cell death (apoptosis) assays
  • Cytokine release assays
  • Assays measuring the modulation of cell signaling (phosphorylation events)
  • Assays measuring the modulation of the inflammatory response (immune cell function/recruitment)
  • Receptor binding and receptor activation assays
  • Ligand binding assays

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Immuno-oncology has emerged as one of the most promising treatments for cancer. To support the growing number of companies developing immuno-oncology drugs, Sartorius has developed a suite of assays that allow us to characterize immune cell interactions during the development process. We perform the following assays as services:

  • Activation  
  • Proliferation  
  • Cytokine production
  • Regulation/suppression
  • Cell death/apoptosis
  • ADCC
  • ACDP

Sartorius employs the iQue Screener PLUS to reduce the time and amount of sample needed by obtaining multiple phenotypic and functional readouts in a single assay. Our team of experts works to optimize your process and accurately interpret critical data. We also design and develop custom assays to meet the specific needs of each biomanufacturer.

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Antibody-dependent cell-mediated cytotoxicity (ADCC) is an important mechanism of action of therapeutic antibodies, especially in oncology. Determining the ADCC activity is therefore a critical step in the development of antibody drugs, to characterize either as primary or secondary mode of action or in the case of some therapeutics to demonstrate its absence.

Customizable Biological Assay Solutions

Sartorius has developed a range of robust ADCC assay platforms that address the well-known variability issues of these assays by using plate-based or iQue Screener PLUS formats. Depending on the drug developer’s needs and requirements, the Sartorius ADCC assays can be performed using peripheral blood mononuclear cells (PBMCs), which are harvested on the day of assay from a variety of genotyped donors. Our ADCC assay portfolio also includes surrogate ADCC assays that utilize engineered cell lines stably expressing the FcγRIIIa receptor to negate donor-specific variability and provide viable solutions for validation of these complex assays.

Using our platform methodology, we can develop an ADCC assay to meet your requirements.  Custom ADCC along with our qualified ADCC assays for common targets can be tailored to address your changing needs throughout the development process with a range of effector:

  • Total PBMCs
  • Lymphoid-Enriched PBMC
  • Natural Killer (NK) Cells
  • Promega ADCC Reporter Cells
  • KILR CD16 Effector Cells

A range of Fc receptor binding assays and in-depth glycan analysis are also available to complement the functional ADCC.

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Antibody-Dependent Cellular Phagocytosis (ADCP) is an immune mechanism through which antibody-bound target cells expressing tumor or pathogen-derived antigens on their surface activate FcγRs (predominately FcγRIIa) on the surface of monocytes and macrophages to induce phagocytosis. ADCP results in the internalization and degradation of the target cell through acidification of the phagosome and, with that, clearance from the body.

Robust and Customizable ADCP Assay Solutions

At Sartorius, we offer ADCP using the iQue screener plus. This method measures phagocytosis mediated by FcgRI, IIa, and IIIa activation using PBMCs with the potential to multiplex data.  

We can further customize simultaneous ADCC readouts to collect information on other cell populations and cytokines to fully investigate your antibody’s functional response.

A plate-based reporter bioassay to measure ADCP, allowing potential for validation is also available.

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Complement Dependent Cytotoxicity (CDC) is a well-characterized effector function of IgG and IgM antibodies. CDC is initiated by binding of the complement protein C1q to the Fc domain of mAbs, which triggers a proteolytic cascade and results in the formation of the membrane attack complex and subsequent target cell death through lysis.

The ability for a therapeutic antibody to activate complement and perform CDC needs to be evaluated during product characterization.

Robust Platform to Measure CDC  

Sartorius offers a robust platform that allows developers to qualify and measure CDC activity for a range of targets. We have developed off-the-shelf solutions that are ready for use and also offer fully customized development for new targets. Both rabbit and human complement can be sourced for CDC assay development and testing.

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For antigens that are difficult to express in a soluble fashion, cell-based binding assays allow measurement of the binding interaction to the native antigen. And because binding assays are a key component of molecule characterization, particularly for antibody-based therapies, Sartorius has developed a variety of methodologies to assess cell-based binding using different technologies, including:

  • Flow Cytometry with iQue Screener PLUS
  • Meso Scale Discovery (MSD) Resources

Cell-Based Assay Development Support

Our expert scientific team can work with you to develop an assay to assess binding to your target of choice using either technology. We can also support assays on the MSD that can be validated to GMP for use in lot release. And our range of assays uses a variety of cell lines to assess binding to common targets, such as CD20, HER2, tmTNFa, as well as methods to assess cell-associated vascular endothelial growth factor (VEGF).

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Related Assets


ELISA - Conception and Applications

Since its conception in the early 1970’s the Enzyme Linked Immunosorbent Assay (ELISA) has been a primary method of analyte detection.

Read Blog Article

Development of a Platform Live Cell Binding Assay Using an iQue® Scree...

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