Table 1. Epithelial barrier parameters of differentiated 16HBE cell layers.

	Potential difference (mV) (apical negative)	TER (Ω × cm2)	Short-circuit current (μA/cm2)	14C-Mannitol flux rate (pmol/min/cm2)
Mean ± SEM	−4.4 ± 0.2	713.7 ± 30	6.8 ± 0.4	2.1 ± 0.1
Range	−1.4 to −7.1	266–1524	2.3–15.8	1.5–4.0

Seeded at 1.0 × 10⁶ or 2.0 × 10⁶ cells per 4.2 cm² PCF on day 0, potential difference, TER, short-circuit current, and ¹⁴C-mannitol flux rate were measured as described in ‘Materials and methods’ section on days 6, 7, or 8. The data include n=57 cell layers treated under control conditions in various experiments.