Fig. 2.

Formation of cell sheets and barrier function. The ability to form a stratified barrier epithelium was examined in three independent NHB cell lines, with a representative NHU cell line provided for comparison purposes. (A) Representative haematoxylin and eosin-stained NHB and NHU cell sheets showing multi-layered tissue structures formed 7 days post-seeding onto membranes in serum- and 2 mM calcium-containing medium. Scale bar ≡ 100 µm. (B) Trans-epithelial electrical resistance (TEER) measurements taken daily. Day 0 measurements were taken 24 h after seeding the cells onto membrane inserts, directly before the medium was changed to increase the calcium concentration to 2 mM. (C) Immunohistochemical analysis of NHB and NHU cell sheets for CK5, CK7, CK13 and CK14 protein expression. Representative results shown from experiments performed on n = 3 independent NHB cell lines. Scale bar ≡ 50 µm.