Determination of IGFBP7 protein levels in conditioned media from human ESCs and GE cells. The conditioned media of subconfluent cells was collected at the indicated times and stored frozen until use. (A) Representative standard curve obtained by ELISA using recombinant human IGFBP7 in PBS containing 0.1% BSA. Data represents the means of four replicates. (B) IGFBP7 levels in conditioned media over time. The conditioned medium of GE cells was measured at the 24 h time point only. Gray column; IGFBP7 levels in the medium of ESCs treated for 24 h with IGFBP7 siRNA (10 pmol). The data represents the means ± SE of three separate cultures, assayed in duplicate.