A review on the mechanism and potential diagnostic application of CRISPR/Cas13a system.

Clustered regularly Interspaced short palindromic repeats (CRISPRs) and CRISPR-associated (Cas) proteins form a natural immune defense system in prokaryotic species, with approximately 90% of archaea and 40% of bacteria possessing these systems, highlighting their widespread role in microbial immunity. Among these, the CRISPR/Cas13a system, guided by a single-stranded RNA (crRNA), selectively targets RNA sequences and has shown immense potential in developing sensitive diagnostic tools. Recent advancements have combined Cas13a with amplification methods and lateral flow detection (CRISPR/Cas13a-LFD), improving its application for rapid and accurate RNA detection. In this review, we explore the history, structure, and functional mechanism of the CRISPR/Cas13a system, focusing on its diagnostic capabilities. We compare CRISPR/Cas13a to conventional diagnostic approaches, highlighting their advantages in sensitivity, specificity, speed, and flexibility for point-of-care application. Given the rapid development of CRISPR-based diagnostics in recent years, the Cas13a system shows great potential as a next-generation platform for accurate, portable, and cost-effective detection of viral and bacterial diseases. Furthermore, we address the existing challenges, including reliance upon amplification and off-target effects, and highlight the need for ongoing research to develop amplification-free systems suitable for clinical application.