Abstract
In drug discovery research, developing a validated and robust in vitro assay is crucial for high-throughput screening and subsequent hit characterization. There are many kinase assay technologies, so an assay developer has several decisions to make prior to undertaking experiments: which assay technology should be used? What are the advantages and disadvantages of a cascade assay compared with a direct assay format? Should the substrate be a peptide or a protein? When using a protein substrate, should it be physiologically relevant? In this perspective article, these questions will be addressed using examples from a study with the human mitogen-activated protein kinase kinase kinase COT.