Provided is a method suitable for concentrating the viruses present in the environment, food or biomaterials in fields such as inspections for ensuring public or food safety and medical examinations, and reagents used therein.
By adding an optimum concentration of polysaccharide such as glycogen to polyethylene glycol (PEG) and optimizing the concentration of a salt to be added, the viruses suspended in an aqueous solution can be easily, rapidly and stably recovered at a high recovery rate.