Eosinophil Detection in Nasal Tissues

Nasal tissues including nasal turbinate and septum were fixed immediately with 4% paraformaldehyde solution (Biosesang, Sungnam, Korea), decalcified with 10% EDTA solution for several days, and embedded in paraffin. Anatomically similar sections of nasal tissues were stained with Sirius Red stain for the detection of eosinophils. This stain protocol was followed as previously described with slight modifications. Briefly, sections were stained with Mayer’s hematoxylin (DAKO, Denmark) for three minutes and rinse in tap water followed by a rinse in absolute ethanol. The sections were placed into alkaline sirius red (Sigma-Aldrich, MO, USA) for 2 hours and rinsed well in tap water. The stained slides were cleared by xylene and mount with permount medium^{28 (link)}. A single blinded observer counted eosinophils under a light microscope (×400 magnification) at the inferior turbinate mucosa.