Advantages and application of label-free detection assays in drug screening

BACKGROUND: Adoption is accelerating for a new family of label-free optical biosensors incorporated into standard format microplates owing to their ability to enable highly sensitive detection of small molecules, proteins and cells for high-throughput drug discovery applications. OBJECTIVE: Label-free approaches are displacing other detection technologies owing to their ability to provide simple assay procedures for hit finding/validation, accessing difficult target classes, screening the interaction of cells with drugs and analyzing the affinity of small molecule inhibitors to target proteins. METHODS: This review describes several new drug discovery applications that are under development for microplate-based photonic crystal optical biosensors and the key issues that will drive adoption of the technology. RESULTS/CONCLUSIONS: Microplate-based optical biosensors are enabling a variety of cell-based assays, inhibition assays, protein-protein binding assays and protein-small molecule binding assays to be performed with high-throughput and high sensitivity.