Evom ohmmeter

Trans-endothelial electrical resistance (TEER) was measured every 24 hr following iBMEC seeding. Resistance was recorded using an EVOM ohmmeter with STX2 electrodes (World Precision Instruments). TEER values were presented as Ωxcm2 following the subtraction of an empty transwell and multiplication by 1.12 cm² to account for the surface area. TEER measurements were measured three independent times for each sample and at least twice for each experimental condition.

Human colonic T84 cells were routinely maintained in a ratio of Dulbecco’s modified Eagle’s medium (DMEM) and Ham’s F-12 medium supplemented with 10% foetal bovine serum (FBS), 100 units/mL penicillin, and 100 µg/mL streptomycin. T84 cells between passages 8 and 20 were seeded onto polycarbonate membrane, 12 mm Snapwell permeable support cell culture inserts (0.4 µm pore size; Costar), and grown for 10–15 days during which the media were changed every 48 h. Monolayer resistance was determined using an EVOM ohmmeter with STX2 electrodes (World Precision Instruments, Inc.) (Sheikh et al. 2013 (link)). IB3-1 cells were obtained from the American Type Culture Collection (Manassas, VA). The IB3-1 cell line is a compound heterozygote bronchial epithelial cell line from a CF patient containing one ΔF508 allele and one W1282× nonsense mutation allele. IB3-1 cells were cultured in LHC-8 medium (Invitrogen, Carlsbad, CA) supplemented with 5% FBS, 100 U/mL penicillin, 100 μg/mL streptomycin, 2 mM l-glutamine, and 1 μg/mL amphotericin B (Fungizone).