A method of distinguishing mesenchymal stem cells (MSCs) from fibroblasts is provided. Also provided is a method of increasing a purity of mesenchymal stem cells (MSCs) population in a cell culture. The above-mentioned methods each comprise a step of sorting or isolating the cells by a marker of CD146 from a cell culture derived from a placenta-related tissue. Further provided is a method of assessing purity of mesenchymal stem cells (MSCs) in a cell culture derived from a placenta-related tissue, comprising determining the percentage of cells expressing CD146 in the culture.本發明提供一種區別間質幹細胞(MSCs)與纖維母細胞的方法。本發明亦提供增加細胞培養物中的間質幹細胞(MSCs)群體之純度的方法。上述方法各自包含透過標記物CD146自源自於胎盤相關組織的細胞培養物中分選或分離細胞的步驟。本發明亦提供評估源自於胎盤相關組織的細胞培養物中的間質幹細胞(MSCs)之純度的方法，包含測定該培養物中表現CD146的細胞之百分比。
