3 Methods
3.1 Transepithelial
Electrical Resistance
(TER) and Paracellular
Flow
- TER and paracellular flux is evaluated using a two-
compartment cell culture model. - Caco-2 cells are seeded at a density of 10^5 cells/cm^2 onto
Costar Transwell permeable culture inserts (pore size 3μm,
Corning Inc., Corning, NY, USA) in standard 24-well plates. - Cells are cultivated in GM at 37Cin5%CO 2 and maintained
for 10–12 days until a tight monolayer is formed and a stable
TER is attained. TER of the cell monolayers is measured using
an epithelial volt-ohm meter with a stick-type electrode as per
the manufacturer’s instructions (Fig.1). Only cell monolayers
with a stable TER of 500–700Ωcm^2 and above should be
used. - TER value is calculated via the following equation: TER
[Ωcm^2 ]¼(measured resistance for membrane with cells
[Ω]measured black resistance for membrane without cells
Fig. 1Transepithelial electrical resistance (TER) setup. Caco-2 cell monolayers
are grown in 24-well plates on Costar Transwell permeable culture inserts (3μm
pore size). TER resistance of Caco-2 cell monolayers is measured using an
epithelial volt-ohm meter with stick-type electrodes (E1 and E2). TER
[Ωcm^2 ]¼(measured resistance for membrane with cells [Ω]measured
blackresistance for membrane without cells [Ω])area of the membrane
(0.33 cm^2 )Autoinducer Effects on Mammalian Cells 217