Abstract: Objective： To isolate and culture human periodontal ligament stem cells (PDLSCs) and observe its ultrastructure. Methods: The proliferation and growth characteristics of human periodontal ligament cells were observed in primary culture and colony culture. PDLSCs were isolated by magnetic activated cell sorting (MACS) and ultrastructural characterization was observed by electron microscopy. Results: When the cells were cultured at low density, PDLSCs grew in a colony-like manner. With the exception of a small amount of rough endoplasmic reticulum, ribosomes, and mitochondria, relatively few organelles were found in the cytoplasm, suggesting that they had remained undifferentiated. Conclusion: PDLSCs showed colonylike growth capacity and had ultrastructural characterization with stem cells. This indicated that PDLSCs could act as the appropriate seed cells for cell-based periodontal tissue regeneration.

Key words: Periodontal ligament, Mesenchymal stem cells, Cell culture techniques, Immunomagnetic separation