Hemagglutination test
Liver samples collected from three infected rabbits were frozen and
stored at −70°C. Liver samples were homogenized (20% in
phosphate-buffered saline [PBS]), frozen at –70°C, and thawed
twice. The hemagglutination test (Hu et al., 2016) was carried out in
U-shaped microtiter plates containing 50 μL of PBS (pH 6.5).
Fifty-microliter suspensions of homogenized liver samples were two-fold
serially diluted and placed in U-shaped plates; they were then further
incubated with an equal volume of 1% human O erythrocytes at 4°C, 25°C,
or 37°C. The hemagglutination was visually determined 30 min later. RHDV
isolate WF/China/2007 (GenBank accession number: FJ794180) was used as a
positive control.