Once the murine tracheal epithelial cells form an intact monolayer with a cobblestone appearance, gently rinse the cells with three milliliters of prewarmed PBS. Add three milliliters of animal component-free enzymatic dissociation solution to the dish and incubate at 37 degrees Celsius for five minutes. Gently pipette to dislodge the cells and transfer the suspension to three milliliters of animal component-free enzyme inhibition solution.
Centrifuge the cell suspension at 400 G for five minutes at four degrees Celsius and resuspend the pellet in one milliliter of expansion medium. Count the viable cells using trypan blue and a hemocytometer. Plate P1 cell suspension on a 100 millimeter dish pre-coated with rat tail collagen.
Culture the cells at 37 degrees Celsius with 5%carbon dioxide.
