How would you qualify a discovery assay for a high-throughput screen?

Why

Select a readout aligned to the biology and define the screen objective, control wells and acceptance criteria before miniaturization. Test positive and negative controls over multiple plates, operators and runs. Measure dynamic range, variability, Z-prime or signal window as appropriate, and inspect spatial trends, dispensing order and reagent stability.

Optimize plate maps to detect edges and gradients rather than hiding them. Run a pilot subset of compounds to estimate hit distribution and identify artifacts such as fluorescence quenching or luciferase inhibition. For example, a Z-prime above 0.5 may indicate good control separation under many screening conventions, but cannot establish target specificity or acceptable hit reproducibility.

A strong qualification plan also defines re-test, dose-response, counter-screen and an orthogonal assay. The release decision for a production screen should explicitly distinguish technical readiness from biological selectivity.