Project summary Quorum sensing is a method of cell-cell communication used by bacteria to detect and respond to changes in population density and control behaviors that benefit the group for adaption and survival in their environment (e.g., symbiosis and pathogenesis). My research program is focused on how bacteria use quorum sensing signaling to control expression of virulence genes. Toward this goal, we study quorum sensing gene regulation in Vibrio species, both as relevant pathogens and as established quorum sensing model systems. We focus on the master Vibrio quorum sensing transcription factor LuxR, which is conserved in all Vibrio species and is the core regulator of hundreds of genes. My research group uses microbial genetics to dissect the LuxR regulatory networks of Vibrio species that influence gene expression for virulence. My lab has established phenotypic experiments for each of these pathways, including type III secretion, protease production, biofilm formation, bioluminescence, osmotic stress response, and natural transformation. These experiments are the foundational components of my research program. I am requesting funds to purchase a BioTek Synergy H1 Hybrid Multi-Mode Monochromator Fluorescence Microplate Reader. This microplate reader measures absorbance, fluorescence, and bioluminescence with tunable precision across a wide range of wavelengths with both adjustable temperature incubation and shaking parameters. We routinely perform assays for growth, bioluminescence production, fluorescence and lacZ reporters for measuring gene expression, phenotypic assays, enzyme kinetics, and quantitation measurements of nucleic acids and proteins. For each of these assays, we heavily rely on the high-throughput nature of the microplate reader to conduct experiments in 96-well or 384-well plates with readings at frequent intervals for 24 hours. We are currently using a BioTek Cytation3 that is used constantly by my lab and three other neighboring labs. The 24-hour growth/bioluminescence assays that we perform are severely limiting our time to perform additional assays. The purchase of the Synergy H1 microplate reader will enable my lab to increase experimental output and dedicate this plate reader solely to our lab and prioritize to 24- hour growth/fluorescence assays.