Fig. 1From: Improving detection of JC virus by ultrafiltration of cerebrospinal fluid before polymerase chain reaction for the diagnosis of progressive multifocal leukoencephalopathySchematic diagram of the handling procedures for ultrafiltration and DNA extraction. Standard virus suspensions or CSF specimens were left untreated or concentrated with ultrafiltration. The samples were lysed with Buffer AL, and total DNA was extracted using a QIAamp MinElute Virus Spin KitBack to article page