Researchers in China have developed a new low-cost covid-19 test that quickly delivers accurate results without the need for sophisticated equipment, according to a study published PLoS Pathogens.1 The surging demand for rapid screening and identification of covid-19 poses great diagnostic challenges. Metagenomic next-generation sequencing (mNGS) and reverse-transcription PCR (RT-PCR) have been the most commonly used molecular methods for diagnosing covid-19, but each has its own limitations. For example, sequencing is costly and has a turnaround time of nearly 1 day, while RT-PCR requires specialized equipment and is difficult to deploy at a large scale. A lack of rapid and accurate molecular diagnostic tools has hampered efficient public health responses to the viral threat. In the new study, the researchers developed an alternative covid-19 test by leveraging CRISPR-based technology, which has been widely used in recent years for gene editing. The assay, named CRISPR-Covid, enables high-throughput detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). CRISPR-Covid delivers comparable sensitivity and specificity as mNGS within as short as 40 minutes. When produced at a large scale, the material cost of a CRISPR-Covid test could be less than 70 cents, suggesting that CRISPR-Covid is a competitive alternative not only technologically but also financially. The authors note, “In this study, we developed an isothermal, CRISPR-based diagnostic for covid-19 with near single-copy sensitivity.” and “We demonstrated a CRISPR-based assay for covid-19 that offered shorter turn-around time and great diagnostic value, even in under-resourced settings without the need of thermal cyclers.” Reference
- Hou T, Zeng W, Yang M, et al. Development and evaluation of a rapid CRISPR-based diagnostic for COVID-19. PLoS Pathog. 2020;16(8):e1008705. Published 2020 Aug 27. doi:1371/journal.ppat.1008705.