Figure 2. Immunofluorescence staining of semithin sections from control explants. Antibodies against glial fibrillary acidic protein (GFAP; red) were used to identify glial IF. DAPI dye (blue) was used to label nuclei. In newly detached samples (A), GFAP was present in the end feet of Müller cells (inner limiting membrane, ILM) and in astrocytes (nerve fiber layer, NFL). The outer nuclear layer (ONL), inner nuclear layer (INL), and ganglion cell layer (GCL) were identified with DAPI dye. At 3 days of culture (B), GFAP was detectable throughout the Müller cell cytoplasm, from the ILM to the ONL (arrows). After 6 days of culture (C), the Müller cells were wider and their GFAP+ processes reached the outer limiting membrane (OLM; note arrows). After 9 days in culture, in explants that maintained the retinal structure (D), labeled processes extended beyond the OLM and began to create a continuous layer in the subretinal space (arrows). In samples that lost the characteristic retinal organization (E), nuclei of surviving cells and GFAP+ extensions were randomly distributed, appearing over the OLM (arrows). Scale bar equals 20 µm.