HS4C3-Binding Epitope Contributes to Fas Signaling Figure 2. Activation of caspase-3 and degradation of Nanog are induced in cells overexpressing 3OST-5. (A) Viability of cells overexpressing 3OST-5. Viability was measured as described in Materials and Methods. The values shown are the means 6 SD of triplicate measurements from one representative experiment after normalization against control cells (arbitrary value = 1). (B) Measurement of the rate of apoptosis in mESCs using an annexin V-FITC kit at 2 days after transfection with the 3OST-5 expression construct. The values shown are the means 6 SD after normalization against control cells (arbitrary value = 1). (C) FACS analysis, using the HS4C3 antibody and annexin V, of mESCs at 2 days after transfection with the 3OST-5 expression construct (left graph) or of mESCs cultured for 8 days in the absence of LIF (2LIF) (right graph). The PLOS ONE | www.plosone.org 5 August 2012 | Volume 7 | Issue 8 | e43440