High-Fidelity CRISPR/Cas13a <i>trans</i>-Cleavage-Triggered Rolling Circle Amplified DNAzyme for Visual Profiling of MicroRNA
Ting Zhou, Mengqi Huang, Jinqiong Lin, Ru Huang, Da Xing
Abstract
The clustered regularly interspaced short palindromic repeats (CRISPR) and CRISPR-associated (Cas) (CRISPR/Cas) system innovates a next-generation biosensor due to its high-fidelity, programmability, and efficient signal amplification ability. Developing a CRISPR/Cas-based visual detection system could contribute to point-of-care biomarker diagnosis. Existing CRISPR/Cas9-mediated visual detection methods are limited by the inherent properties of Cas9. Herein, we explored the trans-cleavage ability of Cas13a on ribonucleotide-bearing DNA oligo, eliminated the unavailability of the trans-cleavage substrate for subsequent polymerization reaction, and developed a homogeneous CRISPR/Cas13a-based visual detection system (termed vCas) for specific and sensitive detection of miRNA. The results indicated that vCas can provide a detection limit of 1 fM for miR-10b with single-base specificity and can be used to analyze miRNA in serum and cell extracts. Conclusively, vCas holds a great application prospective for clinical molecular diagnosis.