How to remove the blood cells when isolate MSCs from umbilical cord blood?

Umbilical cord blood mononuclear cells (UCB-MNCs) are purified using Ficoll-Paque and density-gradient centrifugation. The red layer containing blood cells remaining after plasma collection is reconstituted with PBS buffer to the corresponding volume before collecting autologous plasma. Then, the blood suspension is layered on the top of Ficoll, centrifuged for 20 min at 840×g with low acceleration, and no brake at 4°C. The buffy coat is collected and then washed with phosphate buffer saline (PBS) two times by centrifugation at 300×g for 5 min. UCB‑MSC isolation and expansion are grown in 6-well treated plastic plates in a 37°C humidified incubator containing 5% CO2.