Exosomes are ~30 nm-150 nm membrane vesicles secreted by most cell types, in vivo and vitro and these extra cellular vesicles are found in different body fluids such as blood, urine, amniotic and malignant ascites fluids. Tumor and normal cells might contain distinct subsets of microRNA (miRNA) expression profiles. Therefore, monitoring these circulating exosomal miRNAs can be used as biomarkers for early cancer screening and detection.
Exosomes can be purified either by using a traditional ultracentrifugation procedure or by using precipitation protocols. This application note describes the extraction of miRNA and RNA from precipitation purified exosomes derived from cell culture media and serum, using Beckman’s Agencourt RNAdvance Cell v2 kit on a Biomek automation workstation. Automating SPRI (Solid Phase Reversible Immobilization) chemistry provides an easy, automation friendly and robust nucleic acid purification process that does not require centrifugation and vacuum filtration steps. Purified nucleic acids are easily eluted from the paramagnetic beads under aqueous conditions, which provide maximum flexibility for downstream. The RNAdvance cell Biomek method extracted 96 samples in a 96 well plate format in less than 2 hours and provides a streamlined workflow for downstream assays such as qPCR, micro-array and NGS-RNA sequencing applications.