A Scalable, Easy-to-Deploy, Protocol for Cas13-Based Detection of SARS-CoV-2 Genetic Material

Jennifer N Rauch; Eric Valois; Sabrina C Solley; Friederike Braig; Ryan S Lach; Naomi J Baxter; Kenneth S Kosik; Carolina Arias; Diego Acosta-Alvear; Maxwell Z Wilson

To reduce the second hurdle, the visualization of test outcomes, we explored options available for the detection of Cas13 activity. When bound to its target Cas13 catalyzes the non-specific cleavage of RNAs. This target-specific recognition can be detected in many ways, for example either by lateral flow immunochromatography or by fluorescence visualization. Lateral flow test strips are a promising detection method. These strips utilize capillary action to move analytes through a solid support material striped with antibodies that can detect them, resulting in binary readouts. While simple to use and read-they may eventually enable in-home testing-their current availability is limited and they are expensive relative to the costper-test (Fig. 3B, Sup. Spreadsheet) . For this reason, The copyright holder for this preprint (which was not peer-reviewed) is the . https://doi.org/10.1101/2020.04.20.052159 doi: bioRxiv preprint we sought an affordable, scalable, easy-to-interpret, solution for visualization of positive results. In the CREST protocol, we use a P51 cardboard fluorescence visualizer, powered by a 9V battery, for the detection of Cas13 activity instead of immunochromatography (Fig. 2) .