An engineered CRISPR-Cas12a variant and DNA-RNA hybrid guides enable robust and rapid COVID-19 testing

Extensive testing is essential to control the COVID-19 pandemic. This research presents a CRISPR-based diagnostic assay that is robust to viral genome mutations and temperature changes, produces rapid results, can be directly applied to nasopharyngeal specimens without RNA purification, and incorporates a human internal control. Using an engineered AsCas12a enzyme and hybrid DNA-RNA guides, the assay detects wildtype and mutated SARS-CoV-2 within 30 minutes. Clinical testing on 72 COVID-19 patients and 57 healthy individuals showed 100% specificity and positive predictive value, with sensitivity reaching 100% for unpurified specimens.

Kean Hean Ooi, Mengying Mandy Liu, Jie Wen Douglas Tay, Seok Yee Teo, Pornchai Kaewsapsak, Shengyang Jin, Chun Kiat Lee, Jingwen Hou, Sebastian Maurer-Stroh, Weisi Lin, Benedict Yan, Gabriel Yan, Yong-Gui Gao, Meng How Tan