Fig. 1.

XMRV infection in a panel of cell lines. LacZ-encoding XMRV either expressing the XMRV envelope or pseudotyped with the G protein of VSV (white and black bars respectively), were produced in 293T cells by transient transfection. Virus titers were measured by RT-ELISA and equivalent amounts of virus were used to challenge the cell lines indicated. Productive infection was measured after 48 h as the induction of β-galactosidase activity, monitored using a chemiluminescent substrate. Results are given in counts per second.