FIG. 5.

Light and transmission electron microscopy of cells at 3 weeks of culture in the osteogenic xeno-free medium. Sections cut perpendicularly to the surface of seeding. (A) Light microscopy of semithin section. Bar: 10 μm. (B–F) Transmission electron microscopy of thin sections. (B, D) Taken together, the two photos represent a magnification of an area similar to that marked by a square in (A). Mineralizing nodules (arrows) appear numerous. Bar: 2 μm. (C) Contact zones between cells are shown. Bar: 0.5 μm. (E,F) Higher magnification of mineralizing nodules (arrows in E). Bars respectively: 0.5 μm, 0.1 μm. Color images available online at www.liebertpub.com/tec