Cell-based assays are the preferred functional/phenotypic in vitro tools for both discovery biology and evaluation of the activity of biology modulators. In recent years, they have also been widely explored for target engagement assays and as primary readout for membrane-bound targets such as ion channels and GPCRs.
Beyond the classical use of cell-based assays for molecular biology studies (such as Western blot), more sophisticated techniques can be used to drive the success of the discovery of new therapeutic modalities and/or therapeutic agents. While defining the suite of assays required to lead a drug discovery effort, several parameters must be considered. Among the most important are:
- Level of the readout: target proximal markers, distal markers, functional/phenotypic readouts
- The type of cells: laboratory cells lines, iPSC and stem cells, primary cells, species specificity, genomic background and integrity
- The detection modality and/or technology: high-throughput compatible verses sophisticated/multiplexed cellular readouts
In order to allow for the best flexibility and highest success, we have developed broad expertise with multiple cellular models, readouts and techniques. Regarding the evaluation of cellular events at different levels in the path toward a functional response, we have experience in:
- Target proximal readouts: target stability (with reporter gene fusion or immunoassays), target interactors (with split reported systems), target activity (with immunoassays or via LC-MS), secondary messengers (via immunoassays or imaging for calcium as an example)
- Target distal readouts: sub-cellular localization (via split reporter or via imaging), pathway activation (via immunoassays), transcriptional readouts (via reporter assay or qRT-PCR)
- Functional/Phenotypic readouts: Cell cycle (via cytometry), cell proliferation (metabolic and imaging readouts), differentiation (imaging and cytometry), cellular trafficking (via imaging), metabolic activity (metabolic assays), morphology (imaging), other disease are specific readouts (ADCC as an example)
In terms of cellular models; in addition to a cell bank with 100+ common laboratory lines, we have extensive experience in the handling of primary cells (PBMCs, fibroblasts, endothelial cells, hepatocytes, astrocytes and neurons), stem cells, and complex co- and mixed-cellular assays (astrocytes-neurons, blood-brain barrier models and spheroids).
We have multiple state-of-the-art technologies for cellular assays that we apply to achieve the best outcome tailored to the project requirements. Among them:
- State-of-the-art fluorescence (FI, FP, TR-FRET, Alpha) and luminescence detectors
- Immunoassays (Mesoscale Discovery, SMCxPRO, Erenna Singulex, ELISA detectors)
- Imaging (Acumen, InCell 2000, InCell 6000 confocal with live module)
- Cytometry (BD FACS canto and aria)
- LC-MS (for metabolite quantification)
In addition to cellular assays for functional readouts, we have a long-standing history of cellular assays for in vitro ADME studies. Among them:
- Hepatocyte-based assay (stability and hepatotoxicity)
- Mast cell degranulation assay (for pseudo-allergic reaction prediction)
- CYP induction, lysosomal trapping
- An in vitro blood-brain barrier (BBB) model suitable for predicting brain penetration of circulating molecules.
