Abstract

Advancements in screening technologies employing small organisms have enabled deep profiling of compounds in vivo. However, current strategies for phenotyping of behaving animals, such as zebrafish, typically involve tedious manipulations. Here, we develop and validate a fully automated in vivo screening system (AISS) that integrates microfluidic technology and computer-vision-based control methods to enable rapid evaluation of biological responses of non-anesthetized zebrafish to molecular gradients. Via precise fluidic control, the AISS allows automatic loading, encapsulation, transportation and immobilization of single-larva in droplets for multi-organ imaging and chemical gradients generation inaccessible in previous systems. Using this platform, we examine the cardiac sensitivity of an antipsychotic drug with multiple concentration gradients, and reveal dramatic diversity and complexity in the accurate chemical regulation of cardiac functions in vivo. This proposed system expands the arsenal of tools available for in vivo screening and facilitates comprehensive profiling of pharmaceuticals.