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bioRxiv · 10.1101/2023.01.04.522767

High Throughput Viability Assay for Microbiology

Meyer, C. T.·Lynch, G. K.·Stamo, D. F.·Miller, E. J.·Chatterjee, A.·Kralj, J. M.
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Abstract

Counting viable cells is a universal practice in microbiology. The colony forming unit (CFU) assay has remained the gold standard to measure viability across disciplines; however, it is time-intensive and resource-consuming. Herein, we describe the Geometric Viability Assay (GVA) that replicates CFU measurements over 6-orders of magnitude while reducing over 10-fold the time and consumables. GVA computes a samples viable cell count based on the distribution of embedded colonies growing inside a pipette tip. GVA is compatible with gram-positive and -negative planktonic bacteria, biofilms, and yeast. Laborious CFU experiments such as checkerboard assays, treatment time-courses, and drug screens against slow-growing cells are simplified by GVA. We therefore screened a drug library against exponential and stationary phase E. coli leading to the discovery of the ROS-mediated, bactericidal mechanism of diphenyliodonium. The ease and low cost of GVA evinces it can accelerate existing viability assays and enable measurements at previously impractical scales.

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Meyer, C. T., Lynch, G. K., Stamo, D. F., Miller, E. J., Chatterjee, A., Kralj, J. M.. 2023-01-04. High Throughput Viability Assay for Microbiology. https://doi.org/10.1101/2023.01.04.522767

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