 Hi, my name is Tom Scanlon. I'm a research scientist at the Thayer School of Engineering at Dartmouth College. In this video abstract, I would like to share the highlights of a paper recently published in Biotechnology and Bioengineering, authored by myself and my colleagues Sarah Dossel and Carl Griswold. The paper is entitled A High-Throughput Screen for Antibiotic Drug Discovery. The primary research interest of the Griswold Lab is discovery and development of antibiotics for the treatment of infectious disease. We are particularly interested in discovery and engineering of enzymes that degrade cell wall targets as a primary mode of bacterial killing. In this paper, we describe a method for ultra-high-throughput screening of cell wall hydrolyzes. Nature provides an almost unfathomable diversity of unique enzyme activities that could be useful as novel therapeutics in a biomedical setting or as green catalysts in chemical engineering. Despite intense scrutiny over the past few decades, biochemists have only scratched the surface of natural enzyme diversity. Indeed, the vast majority of soil microorganisms cannot be cultured by standard laboratory techniques. The uncultural microbiota thus represents a rich source of novel enzymes. In our paper, we describe a novel platform whereby environmental DNA or single large gene libraries can be cloned into a recombinant expression host and screened for antibiotic activity at a throughput of roughly 5 million clones per day. Just to put that in perspective, that's roughly 5,396 well-plated screening in a single day. Drop-based microfluidics is a powerful methodology for co-encapsulating a genetic determinant with a reporter molecule, usually a fluorogenic probe for desired activity. While this form of chemical compartmentalization is undeniably powerful, it is most compatible with on-ship sorting and requires customized, elaborate setups that are not widely available to most academic researchers. Perhaps the most intriguing aspect of our recent publication was the development of a microfluidic device and workflow for in-vitro compartmentalization without any of us having any experience in fluid dynamics, photolithographic fabrication, or microfluidics. Provided access to a compressed gas source, the entire droplet-generating system that we describe in the paper can be purchased for less than $250. Critically, our approach involves creation of agarose and oil emulsions in which recombinant microorganisms are co-emulsified with bacterial pathogens. The antibiotic-producing microbes secrete products of the gene library, which are concentrated in picoliter droplets and the antibiotic activity can thus be acid using a fluorescent viability dye. By using a solidified hydrogel aqueous phase, we can use standard flow cytometry to screen at sorting rates that exceed 3,000 events per second. Proof-of-concept experiments demonstrate efficient selection of antibiotics creating yeast from a vast excess of negative controls. In addition, we have successfully utilized this technique to screen a metagenomic library for secreted antibiotics that killed the human pathogen staph aureus. I hope you enjoy reading our paper. Please contact the corresponding author, Cowabhers-Wald, with any questions you might have. Thank you very much.