The effects of different blood derivatives on trans-epithelial electrical resistance. Cells incubated with fetal bovine serum (FBS), human peripheral serum (HPS), UltraGRO human platelet lysate (HPL), and PLTMax HPL demonstrated significantly higher TEER values compared to the control group. However, there was no significant differences among FBS, HPS, UltraGRO, and PLTMax on day 3 after the cells reached confluency. UltraGRO: Human platelet lysate from Helios pharmaceutical. PLTMax: Human platelet lysate from Mill Creek pharmaceutical. * indicated p <0.01. ** indicated p <0.01 compared to the control group that was without any blood derivative.