SARS-CoV-2 Detection Using an Isothermal Amplification Reaction and a Rapid, Inexpensive Protocol for Sample Inactivation and Purification

ABSTRACT

As the current SARS-CoV-2 pandemic spreads, the need for more diagnostic capabilities is great. In order to address this need, we have developed a highly sensitive RT-LAMP assay compatible with current reagents, that utilizes a colorimetric readout in as little as 30 minutes. In addition to this, we have developed an inexpensive pipeline to further increase sensitivity without requiring highly specialized equipment. A rapid inactivation protocol capable of inactivating virions, as well as endogenous nucleases, was also developed to increase sensitivity and sample stability. This protocol, combined with our RT-LAMP assay, has a sensitivity of at least 50 viral RNA copies per microliter in a sample. To further increase the sensitivity, a purification protocol compatible with this inactivation method was developed. The inactivation and purification protocol, combined with our RT-LAMP assay, brings the sensitivity to at least 1 viral RNA copy per microliter in a sample. We hope that this inactivation and purification pipeline, which costs approximately $0.07 per sample and which uses readily available reagents, will increase the availability of SARS-CoV-2 testing, as well as expand the settings in which this testing can be performed.