Early Perspective.

The cellular thermal shift assay (CETSA) was introduced in 2013 as a means to assess drug binding in complex environments such as cell lysates, live cells, and even tissues. The assay principle relies on the well-proven biophysical concept of ligand-induced thermal stabilization of proteins, which in CETSA applications is measured as a persistent presence of soluble protein at elevated temperatures. Given its recent development, we have just started to learn about the benefits and pitfalls of the method as it is applied to a growing number of protein target classes, the majority of which are intracellular soluble proteins. One of the early technology developments concerned the transfer of the original assay procedure from PCR tubes and Western blot detection of soluble protein to a homogeneous assay in high-density microplates. A move to high-throughput formats is essential for a more systematic application in drug discovery settings, as well as in academic efforts for validating chemical probes through studies of structure-activity relationships. This perspective aims at providing an overview of knowledge gained in microplate formatting of CETSA and makes an attempt at forecasting future applications.