To develop such a technique, thick (400 600 μm) sections of the rat, mice, calf or postmortal human brain were fixed in paraformaldehyde, dehydrated in a series of ethanol and finally immersed in methyl salicylate.
Selected samples of brain were fixed in 5% phosphate buffered formalin for 24 h, and 700 µM thick sections were cut using a Leica vibrotome.
Biopsies from liver, kidneys, spleens, lungs and brain were fixed in 10% buffered formalin solution for 12 hrs and processed into paraffin blocks.
The main organs such as liver, lungs spleen, kidneys, heart and brain were fixed in 4% paraformaldehyde, embedded in paraffin, and sectioned.
Ileal Peyer's patches, intraperitoneal lymph nodes, spleen, bladder, lung, kidney, pancreas, spinal cord and brain were fixed in either 10% formalin (2 each) or perfused (2 each) with buffered 4% paraformaldeyde before paraffin embedding.
For histopathological analysis, half organ samples of lung and brain were fixed in 10% phosphate-buffered formalin (Fisher Scientific), and mucicarmine and hematoxylin & eosin (H&E) stainings were performed by technicians at the Department of Pathology at Duke University.
