Separation and purification of enveloped and non-enveloped viruses from water samples using an aqueous two-phase system

In this study, a new strategy for enriching viruses in water was developed to improve the detection of viruses in environmental samples. The virus was enriched from water by aqueous two-phase system (ATPS), and the recovery and purification were characterized by tissue culture median infection dose (TCID50) and total protein removal rate. The isolation and purification methods of envelope virus (H1N1) and non-envelope virus (human adenovirus type 5, HAdV-5E) were established and optimized. The results of ATPS were compared with those of membrane filtration, polyethylene glycol precipitation and ultrafiltration. Using ATPS, both viruses were enriched in interphase due to the combined action of volume exclusion and bottom stage salting out. Under the optimum conditions, the recoveries of H1N1 and HAdV-5E were 94.87 ± 2.37% and 96.22 ± 4.71% respectively, and the total protein removal rates were 43.02 ± 5.21% and 71.01 ± 6.34% respectively. Compared with conventional methods, ATPS showed superior performance in recovering virus content and water volume, and the average recoveries were 94.06% (H1N1) and 90.07% (HAdV-5E). Therefore, ATPS had superiorities of high recovery, simple operation and maintaining virus particle activity(Fig. 1).