Figure 4.

Indirect immunofluorescence staining was performed on lung sections from control (NID1^+/–; a, d), NID1^–/– (b, e), and NID2^–/– (c, f) mice. Paraffin-embedded lung sections were incubated after antigen retrieval with antibodies directed against nidogen 1 (a–c), nidogen 2 (d–f), and collagen IV (g–i). Cryosections were used for staining with antibodies directed against the laminin α5 chain (j–1). Secondary antibodies conjugated to Alexa 488 (green) and Alexa 594 (red) were applied to detect the primary antibodies. Arrows, basement membranes (BMs) of large airways; asterisks, alveoli and BM of alveoli; arrowheads, vessel BMs. Scale bar = 90 µm.