Fig. 3.

Changes of TEER and corresponding cell numbers and junctional length. a A plot of the individual transepithelial electric resistance (TEER) of clone 2 to the corresponding number of cells is shown. This demonstrated that, from confluence to the state of differentiating barrier, the values dropped reciprocal to the increase in number of cells, then increased to the level of full barrier properties, though the number of cells was even higher than in previous states. If the TEER solely depended on cell numbers at the state of full barrier, we would have expected values that followed the ideal logarithmic curve. b Similar effects were observed when we drafted TEER to the corresponding measurements of clone 2 of junctional length in µm/0.1 mm², where the increase of TEER under full barrier properties also did not follow a reciprocal curve. c. To differentiate if the TEER per cell–cell junction would remain constant, we multiplied the TEER with the corresponding junctional length of the same experiment. This revealed that, during the initial differentiation from confluence to differentiating barrier, the TEER per junctional length stayed nearly constant from 14.2 ± 3.1 Ω mm to 10.0 ± 5.9 Ω mm, while a significant increase to 20.7 ± 8.8 Ω mm was observed under full barrier conditions (n = 8, *p < 0.05, two-way ANOVA)