Virus isolation
Hepatocellular carcinoma epithelial cells (LMH)
(Kawaguchi et al., 1987) were cultured
with 2 µg TCPK Trypsin/mL in T25 culture flasks and infected with 0.5 mL
of the NDV-positive samples. Cells were incubated at 37 °C until giant
cell formation was observed or for up to 7 days before initiating a
second passage following a freeze/thaw cycle. Further confirmation using
hemagglutination (HA) and hemagglutination inhibition (HI) tests were
conducted on the supernatant culture medium
(OIE, 2012). Isolated viruses were
aliquoted and kept at -80 0C until further use.