Fig. 3.

Influence of FBS concentration on Calu-3 monolayer resistance. Each well was seeded at the same Calu-3 cell density (5.0 × 10⁴ cells/well) with increasing concentrations of FBS (2%, 5%, 10%, and 15%). Subsequently, TEER was recorded each day for up to 14 days and is presented in ohms·cm². FBS produced a concentration-dependent effect on resistance of the monolayer. TEER values for both 2% and 5% were statistically significant from those of both 10% and 15% on nearly every day tested (with the exception of days 3 and 8). Although a similar trend was observed using 10% and 15%, a FBS concentration of 10% was determined to be the ideal concentration due to the more consistent TEER values recorded on days 10 through 14 as compared with the more variable values observed for the cells cultured in medium supplemented with 15% FBS over the same time period.