Figure 3

Protein secretion by embryoid bodies into conditioned media. (A) Total protein content of the conditioned medium (CM) collected at each time point examined as determined by bicinchoninic acid did not significantly vary over time. (B) Enzyme-linked immunosorbent assay results revealed that BMP-4 protein content was similar as embryoid body (EB) differentiation progressed over time. (C, D) Between EB-CMs, IGF-2 protein increased significantly over time in CM at day 12 (CM 12) compared with CM at day 6 (CM 6) and at day 9 (CM 9); VEGF-A increased in CM 12 with significance compared with only CM 6. Results indicate the mean ± standard error (n = 6). Analysis of variance: *P < 0.05 compared with CM 6 and CM 9, †P < 0.05 compared with CM 6. BMP-4, bone morphogenic protein; IGF, insulin-like growth factor; VEGF-A, vascular endothelial growth factor-A.