Single-Step CRISPR/Cas13a Assay for detection of small RNAs in Saliva : a proof-of-concept study

We describe a proof-of-concept study of a rapid, single-step CRISPR/Cas13a assay using Leptotrichia wadei (LwCas13a) for the detection of small RNA (miRNA) biomarkers in saliva, and compare its performance to real-time PCR (RT-PCR).

The single-step Cas13a assay was evaluated against RT-PCR for its detection efficiency, sensitivity, specificity, and its ability to function in a complex biological matrix. A proof-of-concept test was conducted on patient saliva samples to detect a known oral cancer biomarker, hsa-miR-21-3p RESULTS: The Cas13a assay successfully detected candidate miRNA at picomolar concentrations in both in vitro and saliva samples, demonstrating sensitivity and specificity comparable to RT-PCR. Notably, the assay provided discernible detection of the cancer biomarker directly in patient saliva without the need for RNA extraction or reverse transcription steps.

The proposed single-step CRISPR/Cas13a assay may be developed into a promising platform for developing quick and affordable point-of-care diagnostics for cancer and other diseases, circumventing the need for expensive and time-consuming sample preparation steps.