Histological features of inflamed tissues after CO/CFA or IFA injection into murine air-pouches. (A): May-Grumwald-Giemsa staining of sections (1.5 μm) obtained from historesin embedded tissues, showing morphology of the air-pouch 14 days after IFA injection. (B) to (G): toluidine blue staining on cryostat sections (10 μm). In (B) skin morphology of an untreated mouse, with the epidermal layer (e), the dermis (d), the subcutaneous tissue (or hypodermis) consisting mainly of adipose tissue (a), represented by white globular cells and skeletal muscle cells (sk), stained in light blue. From (C) to (G) the response to CO/CFA injection. On day 3 (C), granulomatous tissue (g) can be localized under the skeletal muscle layer (sk), with increased thickness on day 7 (D) and day 14 (E). Proliferation of fibrotic tissue (not shown with this staining) and reduction of granuloma tissue occurred between day 21 (F) and day 28 (G). Pictures are representative of 10 distinct analyses. Bar, 150 μm.