MicroRNA Detection and Target Identification

Katherine E. Richards, David B. Go, Reginald Hill

Tamas Dalmay

MicroRNA detection and quantification are commonly explored techniques for diagnostic and prognostic predictions. Typically, microRNAs are extracted and purified from a biological source, converted into complementary DNA (cDNA), and amplified using real time polymerase chain reaction (RT-PCR). The number of RT-PCR cycles required to reach the threshold of detection provides a relative quantification of the target microRNA when this data is normalized to the quantity of a control microRNA. This methodology has several drawbacks, including the need to artificially amplify the target microRNA for detection as well as quantification errors that can occur due to expression level differences of the control microRNAs for normalization in various sample sources. Here, we provide a technique to quantify actual concentrations of target microRNAs directly from any biological source without the requirement of these additional steps. In addition, we describe an alternative approach for obtaining exosomal microRNAs directly from biological samples without the use of harsh detergents and RNA isolation.