IBDV Colonization in ILP Cells

In order to detect whether the IBDV colonized in the ILP cells at the early stage, the duodenum and cecal tonsil from the infected birds were collected. Sections of the cecal tonsils and duodenum were then fixed in 10% formalin solution and prepared as previously described [9 (link)]. The IBDV antigen was detected using a monoclonal anti-IBDV-VP2 antibody (a kind gift from Professor Aijian Qin, Yangzhou University, Yangzhou, Jiangsu, China) at a dilution of 1:10,000. The secondary anti-mouse IgG HRP-labeled antibodies were used according to the manufacturer’s instructions. DAB (DAB peroxidase substrate Kit, ZSGB-bio, Beijing, China) was used to visualize the enzyme-linked complex. Sections were observed by light microscopy.