Figure 1.

Low-power images of alveolar field. (A) Air-filled lung with calcein red–orange loaded into alveolar epithelial cells. Epithelium fluoresces red; alveolar liquid lining layer and air appear black. (B) Single alveolar edema model. Calcein red–orange labels the alveolar epithelium. Albumin solution labeled with green fluorescent 2′,7′-bis-(2-carboxyethyl)-5-(and-6)-carboxyfluorescein (BCECF) fills a single alveolus. All other alveoli are air-filled, with BCECF labeling the liquid lining layer. Images were obtained with a ×10 air objective.