Nucleic acid detection with CRISPR-Cas13a/C2c2.

Area of Science:

• Molecular Biology
• Biotechnology
• Genetics

Background:

• Nucleic acid detection is crucial for diagnostics, pathogen identification, and disease monitoring.
• The CRISPR-Cas13a system offers RNA-targeting capabilities with collateral enzymatic activity.
• Existing methods may lack the speed, sensitivity, or specificity required for point-of-care applications.

Purpose of the Study:

• To develop a rapid, inexpensive, and highly sensitive nucleic acid detection platform.
• To leverage the collateral activity of Cas13a for diagnostic purposes.
• To create a versatile tool for pathogen detection, genotyping, and mutation identification.

Main Methods:

• Combined Cas13a's collateral ribonuclease activity with isothermal amplification.
• Developed a CRISPR-based diagnostic platform named SHERLOCK (Specific High-Sensitivity Enzymatic Reporter UnLOCKing).
• Utilized SHERLOCK for detecting specific viral strains (Zika, Dengue), bacteria, human DNA, and cell-free tumor DNA mutations.

Main Results:

• Achieved attomolar sensitivity and single-base mismatch specificity in nucleic acid detection.
• Demonstrated SHERLOCK's capability to detect various targets including viruses, bacteria, and human DNA.
• Showcased the potential for lyophilizing reagents for cold-chain independence and field deployment on paper.

Conclusions:

• SHERLOCK provides a powerful CRISPR-based diagnostic tool for rapid and sensitive molecular detection.
• The platform's versatility extends to pathogen identification, genetic analysis, and cancer mutation detection.
• Lyophilization and paper-based reconstitution enable SHERLOCK for accessible, point-of-care, and field-based applications.