(A) Quantitative RT-PCR of TERT, TR, and OCT4 in GFP, F-TERT, TR, or F-TERT+TR overexpressing hESCs. Expression level is relative to GFP hESCs and normalized to GAPDH. Error bars represent the SEM of three biological replicates taken 1 week apart. (B) TRAP assay of whole cell extracts from GFP, F-TERT, TR, or F-TERT+TR overexpressing hESCs using decreasing amount of protein (250, 50, 10, 2 ng). (C) Relative telomerase activity of the hESC lines was assayed by QTRAP. Values were set as fold activity relative to the GFP control line (n = 3, ANOVA with Tukey's test, SEM bars). R: TR, T: F-TERT and T&R: F-TERT+TR.