Ignite Academic Theater Presentation

A large-scale microfluidic technology for high-content screening of C. elegans using commercial imaging platforms

• 

  Sudip Mondal, PhD

  Research Associate
  UT Austin

To enable both high-throughput and high-content imaging of C. elegans, we developed an automated microfluidic platform at The University of Texas at Austin. The platform includes a microfluidic-based large-scale polydimethylsiloxane (PDMS) chip with multiple wells designed in a standard multi-well plate format. Under each well, we have designed a densely packed 40 trapping channels in each 96 wells. The channels are uniquely designed with varying widths and channel heights to maintain an aspect ratio of one. The whole 96-well chip can immobilize approximately 4,000 animals simultaneously in lateral orientation using a user-friendly gasket system. The gasket system with one input and output connections are operated using LabVIEW algorithms to prime a new chip to remove all air bubbles, immobilize the animals in all 96-wells × 40 trapping channels per well within 3 minutes, and keep all animals inside the tapered channels during high-resolution imaging. The automated imaging platform can image 15 z-stack images of all trapped animals, capturing their whole volume with a micron resolution in less than 16 minutes. A semi-automated graphical user interface (GUI) loads all the images, identifies the single animal and perform image processing steps to identify the fluorescence-based phenotypes in C. elegans. Using a large field of view optics and required imaging resolutions, we were able to identify subtle fluorescence phenotypes from C. elegans neurons and body wall muscle cells. We have used the platform to identify phenotypes such as small protein aggregates, neuronal intensity and shape, and axonal beading in various disease models in C. elegans relevant for Huntington’s disease, Alzheimer’s disease, and Parkinson’s disease, respectively.

Using this platform, we screened ~250,000 C. elegans growing in a robust liquid culture assay and imaged using a total number of 72 chips. In one of the screens, we tested the efficacy of ~1,000 FDA approved drugs in improving the aggregation phenotype of the polyglutamine-induced aggregation model and identified 4 confirmed hits, one of which has a strong dose-response. The confirmed hit was also verified in multiple genotype background and imaged in our microfluidic platform.

Our robust platform enables high-content screening of C. elegans disease models at high speeds and at low costs. We are interested to collaborate with C. elegans researchers to beta test our technology and to partner with plate imaging companies to co-market our microfluidic chip for high-content imaging needs. We believe this technology will excite the research community to develop and characterize new disease models in C. elegans with subtle phenotypes under a low protein expression. Such models are being developed to better mimic human disease biology and provide useful in vivo drug-in-action information during early drug screening to identify new hits and optimize novel leads.