Fig. 5. Membrane permeability assays of A549 cells using calcein (green-live)/EthD-1 (red-dead) staining. A) Cells incubated in osmolyte solutions for 24 h then imaged. B) Membrane permeability of frozen/thawed cells which had been previously incubated with indicated osmolyte (or media) and cryopreserved in 10% DMSO (±PVA). Scale bar = 50 μm.