About Us

The Chemical Probes Portal is an easily accessible online resource for scientists to find and use small-molecule reagents called chemical probes in biomedical research and drug discovery. A unique feature of the Portal is that these molecules are evaluated by recognised chemical probe experts (the Scientific Expert Review Panel, SERP) and recommendations are provided about how to best use these tools in biological research and drug discovery.

Chemical probes are powerful tools for elucidating the role of a target protein in cells and diseases, and are potential pathfinder molecules for drug discovery. However, using compounds incorrectly, or using poor quality compounds, can produce misleading results ([Arrowsmith _et al_, 2015](https://www.nature.com/articles/nchembio.1867/), [Antolin _et al_, 2022](https://doi.org/10.1093/nar/gkac909)). Chemical probes are potent, cell-active, well-characterised small-molecule modulators of protein function. They are mostly inhibitors, but can also be activators, (ant)agonists or degraders or other kinds of modulators, which can be used to perturb a target protein in biological systems. A particular focus lies on the selectivity of a probe to be able to to unpick the activity of that target in cells or in animal models and learn more about the function of its cognate target and its disease relevance. By making it easier for scientists to identify the best tools for their research, the Portal helps researchers make the most of their resources, increasing the reproducibility of experiments, and accelerating research that brings new medicines to patients.

The Portal includes a range of chemical tools, including small-molecule inhibitors, agonists, PROTACs (proteolysis targeting chimeras), molecular glues, and molecular glue degraders. Criteria for well-validated probes can be found on the Criteria for Probes Page.

The Portal also curates a list of historical compounds, which have been used as inhibitors in the past but are no longer considered probes.

Our Scientific Expert Review Panel (SERP) consists of a diverse group of scientific thought leaders from the areas of chemical biology, medicinal chemistry, pharmacology and related disciplines. SERPs provide guidance on the best chemical probes available for a particular experiment and establish best practices for using them. Compounds are rated out of four stars for use in cell systems and in vivo experiments. The Portal recommends probes with three or four stars. Find out more about the star rating system.