Label-Free CRISPR/Cas9 Assay for Site-Specific Nucleic Acid Detection

Area of Science:

• Molecular Biology
• Biotechnology
• Nanotechnology

Background:

• The CRISPR/Cas9 system revolutionized genome engineering but faces challenges like off-target effects and variable nuclease activity.
• Existing CRISPR/Cas9 assays often rely on labeling strategies that can interfere with Cas9 activity and are time-consuming.

Purpose of the Study:

• To develop a novel, label-free assay for CRISPR/Cas9 activity detection.
• To improve the sensitivity, speed, and specificity of CRISPR/Cas9 assays.

Main Methods:

• A DNA-templated copper nanoparticle (CuNPs)-based assay was developed.
• The assay detects CRISPR/Cas9 cleavage activity without requiring labels.
• Site specificity was demonstrated by assessing the impact of single-base changes.

Main Results:

• The developed label-free assay achieved a low limit of detection (LOD) of 0.13 nM.
• Rapid detection was achieved within 35 minutes post-CRISPR/Cas9 cleavage.
• The assay demonstrated high site specificity, with single-base changes significantly reducing Cas9 cleavage efficiency.

Conclusions:

• The DNA-templated CuNPs-based label-free CRISPR/Cas9 assay offers a sensitive and rapid alternative to traditional methods.
• This assay provides a new paradigm for in vitro CRISPR/Cas9 analysis and potential in vivo applications.
• The strategy enhances the reliability of CRISPR/Cas9 activity monitoring by minimizing assay disturbances.