Histological Scoring of Murine Colitis

Ileum, cecum, proximal colon, and distal colon were fixed in Carnoy’s fixation for 1–2 days before being placed in methanol prior to paraffin embedding. Samples were deparaffinized, cut into 4 μM sections, and stained with hematoxylin or ABPAS. Images were taken with a Nikon Ti Eclipse or Leica microscope. Sections from 4–6 mice were used for blinded colitis scoring, according to established criteria (77 (link), 78 (link)). The number of ABPAS⁺ goblet cells were counted per 10 villi for 5–9 mice per group. A score of 1 refers to mild mucosal inflammation. A score of 2 refers to inflammatory cell infiltrate in the mucosa and submucosa. A score of 3 consists of inflammatory infiltrates plus focal ulcerations. Focal ulceration with mucosa and submucosa inflammatory infiltrate comprises a score of 4. A score of 5 consists of extensive focal ulceration, in addition to mucosa and submucosa inflammatory infiltrate. A score of 6 is indicative of transmural inflammation and extensive ulcerations.