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

Quantitative detection is accomplished using specialized instruments that detect fluorescent probes which report the extent of amplification of the target sequence in real time. While sensitivity is high (on the order of tens of target molecules per microliter), the main limitation is the requirement of real-time thermocyclers, analysis software, and trained personnel for data interpretation. Limitations aside, the core of the technologyamplification of a target nucleic acid sequence by PCR-is robust, sensitive, and makes use of a widely-available enzyme, Taq polymerase. These advantages motivated us to pair PCR with CRISPR-based detection of viral sequences, an approach that has been previously successful for the detection of DNA sequences using Cas9 20 . The thermocyclers required for PCR are expensive, specialized instruments that are generally limited to a professional laboratory. However, the recent DIY-Bio movement has made PCR accessible through the creation of affordable, Bluetoothenabled, field-ready thermocyclers, which can even be battery operated. These versatile thermocyclers can be used in unconventional environments and perform as well as traditional thermocyclers in moderate temperatures [21] [22] [23] . We reasoned that these devices, such as the miniPCR mini16, offer a low-cost solution for the amplification of the viral target material and can make COVID-19 testing widely available (Fig. 2) .