Fig. 3. Perlecan and nidogen colocalize in the matrix of AECs maintained in vitro. AECs at 4 days after isolation were processed for double-label indirect immunofluorescence using a monoclonal antibody against perlecan (A) and an antiserum against nidogen (B). Confocal laser-scanning images of the cells were generated at a focal plane as close as possible to the substrate-attached surface of the cells. The yellow color in the overlay in C indicates where perlecan and nidogen co-distribute. Bar, 10 µm.