T12.5 flasks and the biaxial drive rotator are placed into CO2

incubator for cell cultivation (Fig. 1c).

1. Aspirate the mesoderm induction medium and add 30 mL

hemogenic

endothelium

progenitor

cell

differentiation

medium into the T12.5 flasks of RPM group and add 5 mL

medium into the T12.5 flasks of control group (see Note 5).

2. Put the T12.5 flasks of the RPM group into the biaxial drive

rotator.

3. Place the biaxial drive rotator with T12.5 flasks and the T12.5

flasks of the control group into the CO2 incubator at 37 C

with 5% CO2 and 95% humidity for cell inoculation and

cultivation.

4. Turn on the power of the electronic control system and set it in

random models of speed (0.1–10 rpm).

5. Change the medium with a half-volume fresh hemogenic endo-

thelium progenitor cell differentiation medium every other day

(see Note 6).

6. After 3 days of culture in hemogenic endothelium progenitor

cell differentiation medium, the cell with endothelial morphol-

ogy and tube-like structures emerged in the RPM group

(Fig. 3a). Some differentiated cells contained round cells with

a “grape-like” clusters (Fig. 3a, arrow). The differentiated cells

are characterized by surface marker CD31 and CD34.

3.4

Generation of

Hematopoietic

Progenitor Cells

For the further induction of hematopoietic progenitor cells, the

cells are growth in hematopoietic progenitor cells medium for

another 3–5 days.

1. Turn off the power the electronic control system and carefully

remove the T12.5 flasks from the biaxial drive rotator.

2. Aspirate the hemogenic endothelium progenitor cell differen-

tiation medium and add about 30 mL hematopoietic progeni-

tor cells medium into the T12.5 flasks of RPM group.

Fig. 2 Mesoderm induction from human embryonic stem cells (hESCs). (a) Representative morphology of

differentiated cells after 2 days culture. Scale bars, 100 μm. (b) Representative immunostaining images of day

2 cells for brachyury. Scale bars, 50 μm

Hematopoietic Stem/Progenitor Cell Differentiation in Random Positioning. . .

61