Additional file 2 of Type I collagen facilitates safe and reliable expansion of human dental pulp stem cells in xenogeneic serum-free culture

Additional file 2: Figure S2. Phase-contrast images and quantification of DPSCs cultured on type I collagen and fibronectin in xenogeneic serum-free culture conditions. In cell adherent test, cells were seeded at 2 × 103 cells/cm2 (a sparse cell density) and the images were taken on day 2 post-seeding. Scale bars, 200 μm. ** p < 0.01.