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Hit evaluation and lead identification

Secondary assays are crucial for hit confirmation and evaluation to identify the lead after the primary screening. A panel of secondary assays could be developed through biochemical, biophysical and cellular detection.

(1) Biochemical methods could be orthogonal confirmation and retests;

(2) Biophysical approaches mainly measure the binding affinities between hits and targets through Nuclear magnetic resonance (NMR), Isothermal Titration Calorimetry, dynamic light scattering, surface plasmon resonance techniques;

(3) Cellular assay explores the hit effectiveness and selectivity inside the cell.

Moreover, secondary assays can also be used to evaluate the improvement of structures and pharmacokinetic properties following lead optimization.

Specificity assay: It is necessary to evaluate the limitation and effectivity of a candidate hit by the specificity assays, also filter out the non-specific and promiscuous inhibitors.

Dose response curve: an IC50 or EC50 value of the hit is then generated via testing in the same assay. It will determine the hits activities against targets quantitatively. The curve is also used to investigate the binding interaction between hit and target.

Intellectual property (IP) assessment checks hit structures novelty and patentability in specialized databases.

Chemical amenability: Medicinal chemists assess hits according to their structures, synthesis feasibility, as well as process development including up-scaling and costs.

Mode of action
Determine the mechanism of action for enzymes, inhibitors, and receptor agonists and antagonists; characterize binding kinetics and binding sites by various assays, X-ray crystallography and NMR.


ADMET modeling is applied to estimate physicohchemical properties, pharmacokinetics and toxicity of the hits.

A series of assay platforms have been developed to facilitate hit to lead process by integrating biochemical, biophysical and cell-based techniques. Following clients’ requests to apply the platform into the varieties of targets, we will offer a customized service based on a feasibility study.

X-ray Crystallogoaphy

Customized NMR Services