In vitro Biology – Assays & Screening

A fit-for purpose, robust screening model for evaluating target efficacy is the heart of the drug discovery machine, and crucial in enabling swift progress for a project.

Why choose us

During preclinical development, drug projects require decision-enabling data which describe structure-activity relationship (SAR), confirming or refuting hypotheses related to the design of chemical structure. Assay development competence is of utmost importance in choosing, validating, optimising and implementing a suitable screening assay for a given target as well as supporting SAR evaluations. Enabled by our expertise and long-standing experience, we provide clients with efficient biochemical or cell-based screening assays, as well as biomarker analysis for integration into their drug project’s screening cascade. Our ability to provide stand-alone services regarding biological assays also provides solutions for other Life Science applications. By utilising a variety of models and test systems provided within our assay platform, we can provide complementary analytical data with our reliable, high-quality microplate reader platform instruments.

Link to publication where we used Fluorescence Polarization in a recent client project: Publication Galecto Biotech AB.

Integrated drug discovery

In early drug discovery, screening assay data serves to identify library compounds that potently modulate target function (“Hits”). Likewise, the data provides a SAR understanding of given scaffolds, identifying “leads” and integrating data from the analysis of drug-like properties. In later phases such as Lead Optimisation, results from cellular or functional assays add decision-enabling data to drive the optimisation of lead compounds in Medicinal chemistry campaigns, with the final aim of nominating a clinical candidate drug.

Case 1

Screening data for a GPCR-target functional assay was provided, supporting a biotech client project across several phases in preclinical drug discovery. The assay was validated and optimised for reliability, robustness and overall performance at Red Glead Discovery. An efficient workflow was established in close collaboration with the client, allowing the screening of peptides while reporting results on a weekly basis to the client’s project manager for integration with peptide chemistry design. Through our effort, the project could identify a peptide that potently modulated the target receptor, resulting in a clinical candidate that is currently in phase 3 for an indication in digestive system disease.

Case 2

For the past several years, the assay development team, integrated with other functions within the company, has provided screening data for several projects (Lead identification -Lead optimisation) to a biotech company developing therapies within CNS disease indications. So far, the team has generated five different GPCR-target screening systems which have been validated and optimised to deliver decision-enabling data, driving medicinal chemistry design at RGD. The platform consists of cell-based, functional assays where the receptor stimulus is translated into a measurable cellular response occurring over several days. Exploiting RGD’s full spectrum of services, compound screening is combined with in-house analysis of compound properties to efficiently drive Lead optimisation forward towards the identification of a candidate drug.

Our Approach

The assay development cycle starts with design, selection and feasibility of an assay method which can generate reproducible results suitable for the specified purpose. The assay is then optimized with respect to different assay components and tested against specific acceptance criteria set to verify that the performance characteristics of the assay are reliable for the intended applications. The assay validation is an ongoing process for the assay in use, in which important factors are monitored to ensure robustness and reproducibility of the final assay.

Biochemical and Cell-based Assays



Fluorescence Intensity (FI)

Fluorescence Polarization (FP)

Förster Energy Transfer (FRET)

Time-Resolved FRET (TR FRET)

Homogeneous Time Resolved Fluorescence (HTRF)

AlphaLISA technology

Protein –ligand interactions (LANCE)

Direct protein-ligand interaction (FP)

In vitro hERG safety assay (FP)

Protein-protein interaction (AlphaLISA)

Receptor binding assays

Kinase assays (ADP-Glo)


Protease/Proteinase assays

Mitochondrial toxicity

Enzyme activity, Reporter gene activity

Receptor binding assays, Immunoprecipitation

Protein localization, Degradation studies, 


Binding and residence time assay (NanoBRET)

Apoptosis, Migration

Neuron outgrowth

Phenotype based HCS process

Cell morphology prediction of toxicity


RGD employs EnVision® Multilabel Plate Reader (PerkinElmer) with temperature control:

The EnVision® instrument is a versatile platform enabling high-quality data from a multitude of assay formats: AlphaScreen®, AlphaLISA®, fluorescence, ultra-sensitive luminescence, absorbance, time-resolved fluorescence (TRF) and TR-FRET, for example to detect PerkinElmer’s DELFIA and LANCE assay technologies. Supports use of 96-1543 well plates.

Spectrophotometer: Agilent Cary 60 UV-Vis Spectrophotometer