Human bone marrow samples were obtained from normal person . bone marrow mononuclear cells were isolated with 1 . 073g / ml percoll . mscs were obtained by removing the non - adherent cells 无菌条件下采集正常人的骨髓,用相对密度1 . 073g ml的percoll分离液分离骨髓中的单个核细胞,进而获得msc 。