<i>In vitro</i> culture of adult human alveolar epithelial cells.

<p>(A) Human lung AT2 cell morphology changes more when cultured on rat-tail collagen-coated dishes than on Matrigel-coated dishes. Freshly-isolated human AT2 cells were seeded on collagen-coated or Matrigel-coated tissue culture dishes and photomicrographs were acquired after 12 hours (“Day 0”), 1, 2, and 3 days. Cells on collagen flattened and spread; cells on Matrigel remained cuboidal in shape and accumulated into enlarging “cysts”. Original magnification, 100X. (B) Gene expression analysis of Day 3 cells shows that SP-C, a marker of AT2 cells, is not expressed in cells cultured on collagen; however, its expression is retained on Matrigel.