(119f) Integrated Micro System For High Resolution Imaging And High-Throughput Sorting Of C. Elegans

C. elegans is an excellent model system for studying the genetics of neural development and behavior. In vivo microscopy has been extensively used for phenotypical characterizations and visual screens. Despite the long history, the current procedure is manual, low-throughput, and requires anesthetics. We present a high-throughput automated micro system for high-resolution imaging and sorting of worms without the use of anesthetics. As a part of this system, we developed a microfluidic device that route, trap, and immobilize live animals. The device is a multi-layer design: samples are manipulated in the bottom layer. The top layer includes channels for actuating valves and circulating cooling fluid. The design allows high-resolution and high-magnification imaging using standard microscopes. In order to prevent multiple worms from entering the imaging zone, we designed a self-regulated loading scheme. The nematodes small thermal mass allows it to be cooled and stopped in <1sec without anesthetics. As a result, the time required for sorting is less than 2 seconds. We have developed integrated algorithms which fully automate the processes outlined above and allow for high throughput experiments. To demonstrate capability of this system as a high resolution imaging tool we obtained Z-stack images of green fluorescent protein (GFP)-expressing neurons of a stopped worm with a 100X oil objective. Those images show the resolution of single axons/dendrites, comparable to that of current standard optical microscopy. We show a high-speed sorting of worms with or without GFP.