Fig. 1— Control (a, c, e, g) and chronic obstructive pulmonary disease (COPD; b, d, f, h) lung sections showing elastic fibres in alveolar (a, b, e, f) and airway walls (c, d, g, h), visualised by Elastic van Gieson stain (a–d; black fibres) and by fluorescence confocal microscopy (e–h). a and b) Alveolar rims are indicated by arrows. The confocal images (e–h) are projected images constructed from serial optical slices from 150-μm sections and show autofluorescent elastic fibres (white fibres indicated by white arrows) and, in f), punctate autofluorescent erythrocytes in capillaries of the alveolar wall (white arrowhead). e) Thick fibres in control lung parenchyma mark the rims of the alveoli. COPD lung contains fewer and generally thinner elastic fibres compared with control lung. a, b, e, f) Scale bars = 200 μm. c, d, g, h) Scale bars = 100 μm.