One-Step RT-PCR for Detection of Micrornas in Exosomes Using Droplet Microfluidics

The dysregulation of the microRNAs, small noncoding RNA around 22 bases, accounts for a wide range of diseases including cancer. However, current methods technologies for of the microRNA the detection and analysis of microRNA are limited to the analysis of bulk exosomes, which fails to depict the heterogeneity of the exosome population as individual vesicles. In this work, we developed a reverse transcription polymerase chain reaction (RT-PCR) protocol on a droplet microfluidic platform. We employed the synthetic hsa-miR-21-5p and exosomes extracted from lung cancer patients in the proof-of-concept experiments. The results indicated that our method can detect as low as a single molecule of microRNA per droplet, which is promising for single exosome microRNA assays.