Collins, S.R. et al. Mol. Sys. Biol. 11, 804 (2015).

Eukaryotic cells can sense and move in response to chemical gradients in their environment in a process known as chemotaxis. Despite active research into the sensing mechanism, it remains poorly understood. Collins et al. describe a high-throughput approach for studying sensing and chemotaxis that is based on uniform chemical gradients in individual wells of a microwell plate, which are generated by treating agar-embedded photocaged compounds with a gradient of light. Cells grown in the wells are imaged before and after gradient formation, and their trajectories are measured. Automated analyses were developed and applied to study hundreds of cells per well. Using this approach, the authors tested the phenotypic effects of knockdown by 285 short interfering RNAs, leading to new findings regarding proteins that affect the speed and direction of cell movement.