B-260 Innovative One-Step Extraction of Exosomal micro RNA Without Isolating Exosomes

Abstract Background Extracellular vesicles (EVs) are receiving great attention as biomarkers in liquid biopsies since they are involved in physiological and pathological processes. It is important to obtain a high-yield of nucleic acids because it is possible to prediagnose through the exosome. Methods Here, we report an efficient one-step method for extraction of miRNAs by clustering EVs. When cationic salt is added to samples, anionic EVs tend to form clusters and precipitate within a short time. After centrifugation and adding lysis buffer, miRNA can be extracted with a spin column. Commercial methods were compared to determine the yield of the precipitation method using cationic salt. In addition, we compared with two reference methods to determine the miRNA extraction efficiency. The first one is consisted of two-step method of extracting miRNA from isolated exosome (2 step), which is a general method, where as the second reference method is a commercial product consisting of 1-step extracting miRNA from biofluids. Results Cluster precipitation efficiency using cationic salt was identified through cluster image, SEM, and Western blot. The present method for extract exosomal miRNA has an EV isolation efficiency of more than 3 times compared to the commercial EV isolation methods. In addition, it has excellent exosomal miRNA extraction efficiency from various biofluids such as Saliva, Urine, and Plasma, and can be used as a sample of breast cancer patients. Conclusion These results might be contributed by the sequence of precipitation of exosomes, exosome lysis, and nuleic acid extraction. The rapid and efficient method for extracting exosomal nucleic acids will make an innovative contribution to clinical applications.