# PRICE: direct and robust detection of microRNAs at single-nucleotide resolution

## TL;DR

PRICE is a new method that detects small changes in microRNA sequences with high accuracy, improving cancer diagnosis and research.

## Contribution

PRICE introduces a generalized CRISPR/Cas13a system using PNA blockers for sensitive and specific miRNA SNV detection.

## Key findings

- PRICE detects SNVs in miRNA with a sensitivity limit of ~10 fM.
- PNA blockers selectively inhibit non-target miRNAs, enabling precise detection.
- The method works in serum, cells, and tissues without requiring amplification.

## Abstract

Accurate single-nucleotide discrimination of miRNA is clinically vital because small sequence variations can have significant phenotypic and clinical consequences, yet existing techniques can only detect single nucleotide variations (SNVs) at specific loci. Here, we present a generalized peptide nucleic acid (PNA) mediated CRISPR/Cas13a system (PRICE), enabling detection of SNVs in miRNA sequence without sacrificing the sensitivity. PRICE utilizes PNA blockers fully complementary to non-target miRNAs (e.g., miRNAs containing SNVs at loci of no interest) but not to the target miRNA. These blockers selectively hybridize with and inhibit non-target sequences in samples (serum, cells, or tissues). Only the unhybridized target miRNA then binds to crRNA within the Cas13a complex, activating Cas13a to cleave a fluorescent reporter-quencher linker, generating a detectable signal (~10 fM limit). By designing a panel of PNAs against SNVs, PRICE provides a versatile, amplification-free platform for precise miRNA analysis, advancing cancer diagnosis, prognosis, and biology.

Accurate single nucleotide variations (SNVs) detection is clinically vital, yet existing techniques can only detect SNVs at specific loci. Here, Mao et al present a new generalized CRISPR/Cas-based strategy, termed PRICE, to identify SNVs in miRNA sequences without sacrificing the sensitivity.