Developing assays for kinase drug discovery - where have the advances come from?

Over the past decade, a variety of technologies for the identification and characterization of protein kinase inhibitors have been implemented in the laboratories of nearly every major pharmaceutical and biotechnology company. Although the majority of these assay technologies are highly robust, the ability of many assays to identify compounds that target the kinase of interest in a true biological context remains questionable. Because every in vitro assay represents a trade-off between biological relevancy and factors such as cost, throughput and accuracy, it is important to acknowledge and balance these trade-offs when interrogating a kinase target in such an assay. This review addresses some of the factors that should be considered when developing protein kinase assays, as well as strategies used to address those factors.