Nanopore single-molecule detection of circulating microRNAs.

MicroRNAs (miRNAs) are a class of tiny noncoding RNAs that play an important role in regulating every aspect of cellular activities. Dysfunctional expression of miRNAs disrupts normal biological processes, leading to the development of various diseases including cancer. Circulating miRNAs are being investigated as biomarkers with a potential for noninvasive disease detection. This demands the development of new technologies to accurately detect miRNAs with short assay time and affordable cost. We have proposed a nanopore single-molecule method for accurate, label-free detection of circulating miRNAs without amplification of the target miRNA. This concise protocol describes how to device a protein nanopore to quantify target miRNAs in RNA extraction, and discusses at the end the advantages, challenges, and broad impact of the nanopore approach for miRNA detection.