FIGURE 4.

Retinosomes in bovine RPE. A displays a large field TPM image of bovine RPE obtained from a fresh eye with the white scale bar set to 75 μm. B shows a TPM image of subcellular structures in fresh bovine RPE. Plasma membranes of cells are visible as faint black lines, and nuclei are seen as black filled circles, whereas bright fluorescent spots indicate retinosomes; scale bar, 37.5 μm. C illustrates the normalized fluorescence spectrum obtained as a function of wavelength upon scanning back from 690 to 390 nm (▴) and forward from 380 to 690 nm (●). D, main box displays an en face TPM image of the apical side of the RPE. The two transverse images, one shown at the bottom and one at the right edge, were assembled from a series of z slice images. Scale bar was set to 37.5 μm. E, main box displays an en face TPM image of the RPE with light focused close to the center of the nuclei; the two transverse images were obtained as described in D. The scale bar was set to 37.5 μm. F shows a microscopic fluorescent image of the fraction 1 fatty layer stained with BODIPY493/503. Pictures are representative snapshots of experiments performed in triplicate. The results demonstrate that bovine RPE cells contain bright fluorescent retinosomes, and the lipid droplets purified from the REP homogenates are similar to those imaged in vivo.