Table 1.
Dependency of WSN virus replication on FCS in MDBK cells
| Virus | Virus titers (log10/ml) in the presence of
|
||
|---|---|---|---|
| Trypsin (0.5 μg/ml) | 0.1% FCS | None | |
| A/WSN/33 (H1N1) | 6* | 5 | 1 |
| A/WS/33 (H1N1) | 5 | <1 | <1 |
| WSN-HK (H1N2) | 6 | 2 | 1 |
| A/duck/Ukraine/1/63 (H3N8) | 6 | 2 | 2 |
| A/Los Angeles/2/87 (H3N2) | 4 | 1 | 1 |
| A/duck/Hokkaido/8/80 (H3N8) | 4 | 1 | 1 |
| A/mallard/Alberta/22/76 (H3N6) | 4 | <1 | <1 |
| A/Udorn/307/72 (H3N2) | 6 | 2 | 2 |
| A/duck/Hong Kong/342/78 (H5N2) | 4 | <1 | <1 |
MDBK cells were washed five times with medium without FCS before virus infection. Cells were then infected with egg-grown stock viruses serially diluted 10-fold. After 1-h incubation, cells were then washed five times with medium without FCS and incubated with or without medium containing trypsin (0.5 μg/ml) or 0.1% FCS.
*
Reciprocal of the highest dilution of virus stock at which virus growth was detected by HA.