Fig. 4. Treatment of embryonic astrocytes with neuraminidase led to the release of laminin matrices. When E16 monolayers were fixed immediately after 30 minutes incubation with neuraminidase, no reactivity for laminin was detected (A). At this condition, cells remained attached to the substrate, as shown by DAPI staining (B). When cells were allowed to recover for 1 hour in culture medium after neuraminidase removal (C,D) a laminin matrix with the features of the P0 matrix was assembled by the monolayer (compare with panel B in Fig. 1). Bar, 50 µm.