Fig. 4.

Monitoring virion entry by envelope/tegument co-localization. WT MuHV-4 virions (3 p.f.u. per cell) were left untreated or pre-incubated (2 h, 37 °C) with mAb T2C12 (anti-gH–gL, IgG_2a, 400 µg ml⁻¹). WT (3 p.f.u. per cell) and gL⁻ (50 p.f.u. per cell to give equivalent binding) virions were then bound to NMuMG cells for 2 h at 4 °C. The cells were washed with PBS and either fixed immediately or first incubated (2 h, 37 °C) to allow virion endocytosis. They were then stained for the ORF75c tegument component with mAb BN-8C3 (IgG₁, green), for the gp150 envelope protein with mAb BH-6H2 (IgG_2b, red) and with DAPI (blue). The numbers give the fraction of green signal co-localizing with red signal. The zoomed images show this relationship in more detail.