Appearance of larynx-trachea-lung explants after 24 (A, C, E) and 96 hours (B, D, F) in culture. Explants were grown enrobed in matrigel (A & B) or on filter paper (C, D, E, F). The larynx (l), trachea (t), and lung (lu) are denoted. Glass beads are noted in direct contact with the trachea. Explants grown in matrigel assume more of a 3-dimensional configuration compared to explants grown on filter paper. Chondrocytes in larynx-trachea-lung explants from transgenic mice expressing GFP under the control of the Col2A1 promoter glow when stimulated with a fluorescent light source (E & F). Please note the avid growth of the larynx, trachea and lung in these explant cultures. (All pictures taken at 5X)