Figure 3
From: Long-term culture of cholangiocytes from liver fibro-granulomatous lesions
Lumen formation. A. Epithelial cell in heterogeneous culture plated on top of collagen gel. Section of paraffin-embedded gel stained with hematoxylin eosin (1250×). B. Branching epithelial organoid with lumen formation in collagen gel. Phase-contrast microscopy (250×). C. Branching epithelial organoid in collagen gel showing unistratified epithelium with lumen formation (arrow). Phase-contrast microscopy (250×). D. Mixed cell aggregates (connective and epithelial cells) in collagen gel. The double-headed arrow shows the direction of the preferential distortion of the matrix with alignment of collagen fibers between two aggregates. Note newly formed epithelial ducts following the direction of the aligned fibers. Phase-contrast microscopy (125×). E. Epithelial tubules in collagen gel. Semithin section of Epon-embedded gel, stained with methylene blue. Note unistratified epithelium, mucous-like substance in the lumen and close apposition of connective tissue cells (arrow) (940×). F. Epithelial tubules in collagen gel seen through electron microscopy. Note unistratified epithelium with microvilli protruding into the lumen (arrowhead) and a thin layer of basement membrane (arrow) (13500×).