Aqueous two-phase system to isolate extracellular vesicles from urine for prostate cancer diagnosis

Analyzing extracellular vesicles (EVs) is an attractive approach to diagnosis of prostate diagnosis. However, existing methods of EVs isolation have low efficiency, purity, and long process time, and therefore have low diagnostic ability. To solve these the problems, a two-phase system is adapted to isolate EVs from a patient's urine. Urine from 20 prostate cancer (PCA) patients and 10 benign prostate hyperplasia patients was used to quantify the EVs-isolation ability of an aqueous two-phase system (ATPS) and to compare the diagnostic ability of ATPS with that of the conventional diagnosis method. An optimized ATPS isolates EVs with ~100% efficiency within ~30 min, with 14 times as high as achieved by ultracentrifugation. Afterward, PCR and ELISA are used to detect EVs derived from PCA cells in urine. The results demonstrate that diagnostic ability based on ATPS is better than other conventional diagnostic methods. ATPS can obtain a high quality and quantity of EVs from patients' urine. EVs contain cancer-related protein and genes, so these abundant sources enable diagnosis with high specificity and sensitivity. Therefore, ATPS is a useful tool to increase the specificity and sensitivity of diagnosis.