To begin, with a scalpel, make a precise incision along the two corners of the mouth of a euthanized rat to expose the muscle tissue. Use a pair of tissue scissors to cut the joints of the zygomatic bone and the mandible on both sides of the skull. Then remove the mandible.
Use tissue scissors to cut the bony connection between the nasal cavity and the maxilla. Then use a hemostat to separate the skin of the maxilla to expose the nasal cavity. Sever the connection between the nasal cavity and the orbital bones on both sides at the infraorbital foramen, and remove the nasal cavity.
Place the extracted nasal cavity in a 4%Paraformaldehyde solution for fixation. To decalcify the tissue, wash the fixed tissue with distilled water. Place the tissues in a decalcification solution with a volume 20 to 30 times that of the tissues at room temperature.
Once decalcification is complete, place the tissue in a dehydration box. Transfer the dehydration box to a dehydrator and dehydrate the tissue in increasing alcohol concentrations at different incubation times. Next, place the tissue in anhydrous ethanol for 30 minutes for two cycles.
Following this, transfer the tissue to xylene for five to 10 minutes and repeat, then immerse the tissue in wax for one hour. Place the wax block in embedding cassettes. Remove the wax blocks after they have solidified and trim the wax block.
Insert the trimmed wax block into a paraffin microtome and cut it into three micrometer thick slices. Hematoxylin and eosin staining of the control rats showed well arranged and cilia. The nasal septum mucosa was damaged and detached in the disease group with notable neutrophil infiltration.
