2.2 | Isolation and identification of primary human
nasal epithelial cells (HNECs)
We collected nasal mucosal specimens from patients who met the
diagnostic criteria described previously. We isolated HNECs from these
specimens using the collagenase digestion method (collagenase IV, Sigma
Aldrich, USA). We subsequently performed cytokeratin-19 (CK-19)
immunohistochemical and immunofluorescence analyses.31,
32