CRISPR/Cas12a2 enables ultra-sensitive amplification-free RNA detection.

Area of Science:

• Molecular Biology
• Biotechnology
• Diagnostic Assays

Background:

• CRISPR technologies, including diverse CRISPR-associated (Cas) proteins, are increasingly utilized in diagnostics.
• Cas12a2 is a recently identified RNA-guided nuclease with unique recognition capabilities.

Purpose of the Study:

• To develop and optimize an amplification-free RNA detection method using CRISPR/Cas12a2.
• To achieve ultra-sensitive and versatile RNA detection for diagnostic applications, specifically targeting SARS-CoV-2.

Main Methods:

• Optimization of biochemical parameters (pH, ionic strength, temperature) for Cas12a2 catalytic efficiency.
• Design and cooperative activation of CRISPR RNAs (crRNAs) targeting conserved regions of the SARS-CoV-2 genome.
• Development of a CRISPR/Cas12a2-based assay for RNA detection.

Main Results:

• Achieved sub-attomolar sensitivity (limit of detection of 46.7 aM) for viral RNA detection.
• Demonstrated diagnostic accuracy across 26 SARS-CoV-2 variants.
• Successfully diagnosed 317 clinical samples using the Cas12a2 assay.

Conclusions:

• CRISPR/Cas12a2 is a promising tool for amplification-free, rapid, and versatile RNA detection.
• The platform's adaptability and simplicity are suitable for point-of-care diagnostics.
• This work advances next-generation CRISPR-based diagnostic solutions.