Figure 1.

Model set-up. A volume of 70 µl of collagen was added to the basal portion of the inverted transwell (A) and stored at 4°C. BJ’s were added to the basal membrane 2–3 days later at 3 × 10⁴ in a volume of 80–100 µl and incubated at 37°C, 5% CO₂(B). Epithelial cells (A2EN or VK2) were apically added at 1 × 10⁵ in a volume of 50–200 µl (C). After 6–9 days of incubation at 37°C, 5% CO₂ cells were ready to be used in experiments.