Figure 2.

A549 cell coating. (a) A549 cells cultured on the FNTD crystal surface starting to form a confluent monolayer. A typical island formation with branching cells is clearly visible. Scale bar, approximately 200 μm (b) Magnified section of a confluent monolayer. The cells are tightly packed. It is difficult to contrast cells from the transparent crystal substrate with light microscopy. Scale bar, 10 μm. (c) CM-DiI labeled and proliferating cells forming a confluent monolayer. Scale bar, approximately 200 μm (d) Section of CM-DiI labeled monolayer reveals clear cytoplasmic coloring. Cytoplasmic granules (multilamellar bodies) exhibit a strong fluorescent signal. Scale bar, approximately 20 μm. (e) Cell layer is labeled with Calcein AM to test cell viability. The outer red line indicates the cell membrane. The cell nucleus is defined by the inner red line. A strong perinuclear fluorescent signal with many bright spots (cytoplasmic organelles) and round nuclei indicate good cell viability. Scale bar, 20 μm. (f) Immunofluorescent labeling of cell nuclei by HOECHST 33342 stain. A uniform monolayer of proliferating cells is visible. Scale bar, 10 μm. Images (a), (c), and (d) were obtained by wide field microscopy whereas images (b, e, and f) were obtained in confocal fluorescent mode. Images (a)-(e) show live cell stainings. In (f) cells are fixed with 4% PFA.