FIG. 1.

Characterization of undifferentiated AFSC. AFSC were sorted for c-kit⁺ at passage 2, cultured to passage 5, and analyzed. (A) Light microscopy revealed a spindle-shaped morphology similar to MSC. Scale bar is 100 μm. (B) Flow cytometry analysis showed that AFSC were strongly positive for the MSC markers CD29, CD44, CD73, CD90, and CD105; moderately positive for the ESC markers SSEA4, Sox2, and cMyc; and negative for the ESC marker Tra-1-60/81. Additionally, a subpopulation of these cells retained c-kit expression throughout passaging. (C) Standard G-banding karyotyping of AFSC shows a normal diploid male karyotype. AFSC, amniotic fluid-derived stem cells; MSC, mesenchymal stem cells.