Method of separating hematopoietic stem cells from umbilical cord blood

A method of separating hematopoietic stem cells from umbilical cord blood, wherein, comprising the following steps:

• a) a hydroxyethyl starch solution of approximately 6% is added into cord blood and mixed uniformly, in which the volume ratio of the hydroxyethyl starch solution to the cord blood is approximately 4:1;
• b) after mixing uniformly, they are divided into centrifuge tubes and let stand, then centrifuged to get an upper liquid layer and a lower erythrocyte layer;
• c) the liquid in the upper layer and the erythrocytes in the lower layer are centrifuged respectively, an upper plasma layer and a basal cell layer are obtained after the centrifugation of the upper liquid layer, and the cells in the basal layer are resuspended with the plasma in the upper layer;
• d) a superficial buffy-coat layer is obtained after the centrifugation of the erythrocytes, and the superficial buffy-coat layer is metered with the plasma in the upper layer, and then centrifuged to get a lower cell layer, which is precipitated to remove erythrocytes and then resuspended with the plasma in the upper layer;
• e) the resuspended cells from steps (c) and (d) are combined together, and metered by adding the plasma in the upper layer, then a freezing medium is added and mixed uniformly before transferring into a freezing bag;
• and
• f) cooling with a program-controlled cooling machine and then transferring into a liquid nitrogen tank for storage.