Three different assay variants (a-c) in 96-well plate. Either 12 or 24 replicate wells with MDCK cells were inoculated with tenfold dilutions of A/Memphis/14/96-M (H1N1) as depicted at the bottom of the figure. After 1 h of incubation, the viral inoculums were removed from the top eight rows of the wells; the inoculums were left intact in rows 9–12. After that, standard liquid maintenance medium was added to rows 1–4; 1.2% Avicel RC-581 overlay medium was added to rows 5–12. TPCK-trypsin was included in each overlay medium to produce the final concentration of 1 μg/ml. Immuno-staining 24 h post infection using True Blue substrate.
Matrosovich et al. Virology Journal 2006 3:63 doi:10.1186/1743-422X-3-63