Trackoscope: A Low-Cost, Open, Autonomous Tracking Microscope for Long-Term Observations of Microscale Organisms

Abstract

Cells and microorganisms are motile, yet the stationary nature of conventional microscopes impedes comprehensive, long-term behavioral and biomechanical analysis. The limitations are twofold: a narrow focus permits high-resolution imaging but sacrifices the broader context of organism behavior, while a wider focus compromises microscopic detail. This trade-off is especially problematic when investigating rapidly motile ciliates, which often have to be confined to small volumes between coverslips affecting their natural behavior. To address this challenge, we introduceTrackoscope, a 2-axis autonomous tracking microscope designed to follow swimming organisms ranging from 10µmto 2mmacross a 325cm2area (equivalent to an A5 sheet) for extended durations—ranging from hours to days—at high resolution. UtilizingTrackoscope, we captured a diverse array of behaviors, from the air-water swimming locomotion ofAmoebato bacterial hunting dynamics inActinosphaerium, walking gait inTardigrada, and binary fission in motileBlepharisma.Trackoscopeis a cost-effective solution well-suited for diverse settings, from high school labs to resource-constrained research environments. Its capability to capture diverse behaviors in larger, more realistic ecosystems extends our understanding of the physics of living systems. The low-cost, open architecture democratizes scientific discovery, offering a dynamic window into the lives of previously inaccessible small aquatic organisms.