Dr. Hayden Metsky begins the episode by describing his goal of being able to harness sequenced viral genomes to computationally design diagnostics, therapies, and vaccines. He discusses the value of having methods available that can handle all available genomic data for diverse species for diagnostics and therapies. Next, we learn how CRISPR can be used in a diagnostics setting. Dr. Metsky explains how collateral cleavage broadens the use of CRISPR beyond simply being a tool for genome editing. Advantages and disadvantages of CRISPR-based diagnostics techniques are discussed versus, for example, a more traditional qPCR approach. The discussion then moves on to the computational component of the diagnostics design problem. Dr. Metsky discusses his 2019 Nature Biotechnology paper on the CATCH method for use in hybridization capture and his progression of work in this area (see https://www.nature.com/articles/s41587-018-0006-x). Finally, we discuss his work in designing diagnostics for SARS-CoV-2, CRISPR-based tests being able to gain widespread adoption, and expanding this work beyond viruses to include bacteria as well.