Cell-based bioassays

To determine the bioactivity of your drug product, RSSL offers a bespoke cell-based bioassay service, with analytical methods tailored to your specific needs.


Cell-based bioassays are the primary tool for determining the biological activity of drugs, making them a critical, regulatory-required part of the testing repertoire. Bioassays show the potency of a product in comparison to a reference standard and quantify its ability to produce a certain biological effect.


Companies must generate this information on drug substances during stability and forced degradation studies and to support release testing of the finished product.


Bioassays can be a particularly challenging part of the drug development process as they must be performed in line with regulatory guidelines, including ICH Q2 (R1) and ICH Q6B. At RSSL, we work in partnership with our clients to meet these stringent standards by conducting bioassays in GMP-compliant facilities, staffed by highly trained and experienced technical teams. 

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A Bespoke bioassay service


Our analytical services can be tailored to the needs of our partners to create bespoke services in line with the development goals of each project. We employ techniques such as ELISA, real-time PCR and in vitro cell-based methods to reveal complicated responses to biological activity and capture the required data, whether it is related to protein and gene expression or cell growth. We also have flow cytometry and fluroescent microscopy capabilities which we use to support cell bioassay work and can use for ID analytical methods.


Through these bespoke services, we can determine the potency of monoclonal antibodies, peptides, growth factors and cytokines, as well as confirm the bioactivity of products. These results support you in understanding the active biological molecule, in compliance with ICH Q6B guidelines, and help you characterise its physico- and immunochemical properties, impurities and biological activity. 




Development and validation of bio-activity for biopharmaceuticals and anticancer drugs


A leading innovator in the development and validation of bio-activity for biopharmaceuticals and anticancer drugs. Our comprehensive expertise encompasses a wide range of assays designed to evaluate and ensure the efficacy of these critical compounds:

  • Cell viability assays
  • Cell proliferation assays
  • Glucose uptake
  • Lipid metabolism
  • Cytotoxicity assays
  • USP <87>
  • ADCC (Antibody-Dependent Cell-Mediated Cytotoxicity)
  • ADCP (Antibody-Dependent Cellular Phagocytosis)
  • Bispecific T cell engager assays using NFAT-luciferase and IL2-luciferase systems
    • Target can be on two different cells or on the same cell for enhanced precision
  • Custom TCR T cell activation assays
  • Cytokine reception engagement bioassays 

We also provide tailor-made mode of action cell bioassays, developed in collaboration with our cell engineering partners to create the specific reporter cell line, further underlining our commitment to delivering comprehensive solutions in the realm of bio-activity assessment. 

Watch: Alistair Michel at Promega Biologics Symposium 2023

Watch Alistair Michel as he talks through a case study highlighting the use of custom T-cell line from Promega 2023

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