Small blocks of the cerebral cortex were processed for electron microscopy and were embedded in Epon resin, as previously described in detail.
For the transmission microscopy study, samples were embedded in 3% (wt/v) agar, cut into 1 mm agar blocks, fixed with 3% glutaraldehyde in cacodylate buffer for 3 h and post-fixed with 1% OsO4 for 2 h.
For light microscopy the samples were embedded in the methacrylate Technovit 7100 (Heraeus-Kulzer).
For microscopy, the pellets were embedded in paraffin, cut into 5-µm sections, and stained with alcian blue [29], [30].
For microscopy, all sections were embedded in Entellan (Merck) [ 24].
For microscopy, the pellets were embedded in paraffin, cut into 5-μm sections, and stained with toluidine blue [ 23].
For time-lapse microscopy, the embryos were embedded in 10%gelatin/0.1×× Steinberg's solution, cut out as cuboids with gelatin, and transferred to a new dish containing 0.1× Steinberg's solution with their positions fixed.
To process the sciatic nerve samples for morphological analysis by light microscopy, the samples were embedded in "Leica Historesin," cut with glass knives (3 μm), mounted on slides, and stained with neutral red and black Sudan to visualize the myelin sheaths of nerve fibers.
For optical projection tomography (OPT) microscopy, the immunostained lungs were embedded in low melting agarose (Invitrogen) and imaged on a Bioptonics 3001 OPT scanner equipped with GFP3, Texas Red and Cy5 filters at high resolution (1024 pixels).
Investigation of the nano-extrudates via transmission electron microscopy and atomic force microscopy showed that the nano-crystals were embedded de-aggregated in the extrudates.
