Quantifying Intestinal Neutrophils via MPO IHC

Neutrophils in intestinal tissues were detected using anti-myeloperoxidase (MPO) IHC analysis as described previously^{25 (link)}. Briefly, intestinal tissue sections were deparaffinized, blocked, and incubated with an anti-MPO antibody (1:400; Thermo Scientific) overnight at 4 °C. After incubation with anti-rabbit biotinylated antibody and three times washing, the tissue sections were incubated with avidin/biotin complex (Vectastain ABC Elite Kit, Vector Laboratories). After three times washing, the tissue sections were added with diaminobenzidine (Dako) within 2 min. The mammalian nuclei were visualized by staining with hematoxylin (Fisher Scientific). The tissue sections were then imaged using the Nikon TS2 Microscope system.