Variability of proportions of surface MUC5AC
cells in the small airway epithelium of healthy nonsmokers. Immunofluorescence of MUC5AC staining (red) was processed on cytospin slides prepared from 10th-12th order brushed airway epithelial cells. Shown are examples from 6 individuals. Not shown, IgG irrelevant control, negative for MUC5AC staining. Blue - DAPI. Bar = 20 μm.