CRISPR–Cas12-based detection of SARS-CoV-2
diagnostics immunology/immunity molecular biology
Authors: J.P. Broughton et al
Link to paper: https://www.nature.com/articles/s41587-020-0513-4
Journal/ Pre-Print: Nature Biotechnology
Key Words: Diagnostics; Cas12; DETECTR; RT-LAMP
1. Accurate detection of SARS-CoV-2 in respiratory RNA extracts by CRISPR-Cas12 based technology
2. Easy-to-use and interpret flow assay.
The authors have development an accurate CRISPR–Cas12-based lateral flow assay for detection of SARS-CoV-2 from respiratory swab using RT-LAMP for RNA extraction and targeting the SARS-CoV-2 E and N genes for differential detection. They report 95% positive and 100% negative result detection accuracy from patient samples with known status. The process has an LoD of 10 copies per µL, takes 30-40 minutes from start to finish, has a yes/no answer, is isothermic and does not require bulky instruments for detection, and is pending clinical validation by US FDA.
IMPACT FOR SARS-COV2/COVID19 RESEARCH EFFORTS
Develop diagnostic tools for SARS-CoV-2/COVID19 by using RT-LAMP followed by easy-to-use CRISPR-Cas12-based lateral flow assay.
In vitro study
STRENGTHS AND LIMITATIONS OF THE PAPER
Novelty: Accurately and rapidly detects SARS-CoV-2 RNA by using CRISPR-Cas12 based technology
Standing in the field: Infectious disease diagnostics with CRISPR has been used since 2018, but this is the first published results on SARS-CoV-2.
Appropriate statistics: n.a.
Viral model used: Respiratory swab RNA extracts were used in this study, derived from 36 COVID19 confirmed infections and 42 patients with other viral respiratory infections.
Translatability: It provides a visual and faster alternative to the RT-PCR assay used by the CDC and clinical validation of this assay to US FDA guidance is currently ongoing in a CLIA-certified laboratory.
Main limitations: Limited patient and control sample numbers reduces power.
Slightly less sensitive than the RT-PCR based assay used by the CDC.
Limited clinical use in terms of patient disease state and viral load etc.
Reliant on the quality of the RNA extracts and the required reagents for this, which are currently available in limited amounts.