Fig. 2

Highly proliferative cells in term amniotic fluid are MSCs with osteogenic and adipogenic differentiation capacity. a Representative microscopy images showing morphology of fibroblastic-like cell colonies. Scale bars: 100 μm. b Representative immunophenotypic FACS analyses of cells for MSC and non-MSC surface markers (blue histograms). Isotype controls represented (red histograms). c In-vitro osteogenic differentiation capacity of fibroblastic-like cells visualized by Alizarin Red staining to detect mineralized calcium secreted by osteoblasts. Scale bar: 100 μm. d Adipocyte differentiation visualized by Oil Red-O staining to detect lipid vacuoles of adipocytes. Scale bars: 50 μm. e CFU-F count per 100,000 mononuclear cells plated in media 1, 2, and 3, from five or six donor samples. f, g Growth curve and population doubling time (PDT, measured in hours) of seven MSC sample donors determined for seven passages in four different media. Cells were split every third day and counted at the end of every passage. TAF-MSCs showed a high proliferative activity. Data shown as mean ± SD. X signifies the termination of a sample in the study, due to a proliferation rate of less than 1 over 3 days of cultivation (this occurred in medium 4 only). CFU-F colony forming unit-fibroblasts