Double-staining patterns for transglutaminase tissue-type (TG2) in various tissues during mouse embryonic development. H&E staining (left) and merged images of in situ activities and immunostaining (right) with corresponding fluorescent isothiocyanate (FITC)-pepT26 and an anti-transglutaminase tissue-type (TG2) antibody are shown. Results in panels A and B are for reactions. (A) Spine: AF, annulus fibrosus; NP, nucleus pulposus; VB, vertebral body; BC, subperiosteal bone collar; Pe, perichondrium; CA, cartilage anlagen. (B) Intestine: ME, mucosal epithelium; LP, lamina propria mucosae; MM, muscularis mucosae; Su, submucosa; Me, mesenchyme. Bars = 100 μm.