The Chemical Probes Portal - 2024: update on this public resource to support best-practice selection and use of small molecules in biomedical research.

The Chemical Probes Portal (www.chemicalprobes.org) is a free, public resource, based on expert-reviews, that supports the assessment, selection and use of small-molecule compounds that qualify as chemical probes. These high-quality reagents are essential for exploring the function of individual proteins in complex biological systems, such as cells and organisms, and for validating proteins as potential therapeutic targets. The use of reliable chemical probes accelerates protein annotation in basic biological studies and informs drug discovery. However, the use of low-quality compounds has historically led to erroneous conclusions in biomedical research, and experience shows that failure to follow best practice continues, an issue which the Portal aims to address. Here, we describe the latest updates to the Chemical Probes Portal in both content and functionality. The number of chemical probes and human protein targets covered has increased significantly, with improvements in the processes for obtaining expert reviews and user engagement. Moreover, new functionalities and enhanced tools have been introduced to better support biological researchers in selecting and using the best chemical probes for their studies.