Direct miRNA-hybridization assays and their potential in diagnostics

MicroRNAs (miRNAs) play a significant role in gene regulation and have been shown to be deregulated in various diseases. Specific sets of deregulated miRNAs, termed “miRNA fingerprints”, can distinguish diseased from healthy samples. Detecting disease-specific fingerprints could be used in diagnostics and there are significant efforts towards developing miRNA-detection methods for this purpose. These methods would require the ability to detect multiple miRNAs in a direct, quantitative, specific, and rugged manner.This review discusses potential diagnostic methods for miRNA detection, with the main focus on direct hybridization assays. MiRNA-hybridization assays are categorized into two groups, depending on whether or not they require spatial separation of the labeled probe-miRNA duplex from unbound probe. We find that spatial-separation hybridization assays are able to meet all of our criteria, so they have the most potential for use in diagnostics.

► We develop criteria for a miRNA-analysis method for diagnostic applications.
► MiRNA analysis methods are classified in three different ways.
► We provide detailed analysis of direct hybridization methods.
► We find separation-based methods promising for practical diagnostic applications.