Secondary chicken embryonic brain cell cultures stained with the anti-AIV nucleoprotein specific Moab HB65. Cells were cultured with LPAIV (a-d) or HPAIV (e-h) for 2 h, washed and incubated with fresh medium for 0 h. (a,e) or 24 h (b,f). From the 24 h culture 10% supernatant was transferred to fresh cultures and cultures were incubated for another 24 h without (c,g) or with (d,h) 0.005% trypsin. Magnification: 100×.
Post et al. Virology Journal 2012 9:61 doi:10.1186/1743-422X-9-61