2.6 Pathological and immunofluorescence examinations
Intestinal tissues were collected for the examinations within 10 to 15
min after the death of each mink. Each tissue sample was impregnated
with formalin by soaking in 10% formalin for more than 24 h at room
temperature, and the samples were then soaked in different
concentrations of ethanol from 100% to 70% for 2 h. The samples were
then embedded in paraffin wax and sectioned (6 µm). The sections were
stained with hematoxylin and eosin for histological examination using
light microscopy (Olympus, Tokyo, Japan). The dewaxing sections were
used for immunofluorescence assay(Hou et al., 2018). The sections were
blocked with 0.3% bovine serum albumin in PBS at room temperature (RT)
for 3 h and then washed three times with pre-cooled PBS. This was
followed by permeabilization with 0.4% Triton X-100 at RT, after which,
the sections were incubated for 45 min at RT with anti-SVV VP1 antibody,
which was synthesized in our lab. The sections were then labeled with
secondary goat anti-mouse IgG H&L antibody (FITC) (Abcam, Cambridge,
UK) for 30 min at RT. Finally, the samples were washed with PBS, and
examined by fluorescence microscope (Leica, Wetzlar, Germany).