Fetal Intestinal Epithelial Monolayers

The fetal intestinal epithelial monolayers were cultured on Transwell cell culture inserts (6.5 mm, 3.0 μm pore size; VWR) as described previously (Roodsant et al, 2020 (link)). Briefly, the inserts were coated with 100 μl of 20 μg/ml collagen type I (rat tail, Ibidi) in 0.01% (vol/vol) acetic acid (Sigma-Aldrich) for 1 h at RT, and washed with PBS (Lonza) before use. Human fetal enteroids were collected, and a single cell suspension was obtained by treatment with TrypLE (Gibco, Thermo Fisher Scientific) for 10 min at 37°C. Cells were diluted to 10⁶ cells/ml and 100 μl of cell suspension per insert was seeded (10⁵ cells per insert). The cells were then cultured and differentiated over a period of 14 d as described previously (Roodsant et al, 2020 (link)).