Fig 2.

Extraction of PVpv from cell culture medium by magnetic nanobeads. (A) Extraction of PV1pv or PV1(Sabin) from the cell culture medium by mock-sensitized or PVR-IgG2a-sensitized magnetic nanobeads. (Left) The indicated amounts of the beads were added to the cell culture medium containing PV1pv (1,000 IU in 100 μl) and were then incubated at 4°C for 1 h. The beads were collected with a magnetic separator, and then the titer of PV1pv remaining in the supernatant was measured. The efficiency of extraction (%) by the beads is shown. (Right) The indicated amounts of the PVR-IgG2a-sensitized magnetic beads were added to the cell culture medium containing PV1(Sabin) (1.0 × 10⁵ 50% cell culture infective doses [CCID₅₀] in 100 μl) and were then incubated at 4°C for 1 h. The beads were collected with a magnetic separator, and then the numbers of copies of viral genome on the beads and in the supernatant were determined by real-time RT-PCR. The numbers of copies of viral genome in supernatant without the beads were taken as 100%. (B) The indicated amounts of PVR-IgG2a-sensitized magnetic nanobeads were added to the cell culture medium containing PVpv (1,000, 100, and 10 IU in 100 μl) and were then incubated at 4°C for 1 h. The beads were collected with a magnetic separator, and then the titer of PVpv remaining in the supernatant was measured. The efficiency of extraction (%) by the beads is shown.