Induction of IFN-α/β protein expression in MCMV-infected livers. Organs were harvested from C57BL/6 and 129 mice that were uninfected (0 hours) or infected with MCMV for 36 or 48 hours. Tissue sections were prepared, immunostained, and counterstained with methyl green as described in Methods. Results shown are from uninfected C57BL/6 (a) and 129 (d) mice, C57BL/6 mice after 36 (b) or 48 (c) hours’ infection, and 129 mice after 36 (e) or 48 (f) hours of infection. Insets represent positive cells at a higher magnification. Images were digitally captured at the original magnifications of ×10 and ×40. Scale bars = 100 μm.