Fig. 1.

(A) Schematic illustration of mechanical vibration experiment in this work. Vertical mechanical vibration was applied to the 6-well plate for 10 min every 24 h after the medium change. Phase-contrast microscopic images were acquired every 12 h. Cells were passaged continuously from P3 (Cycle 1) to P5 (Cycle 3). On the 7th day, the samples treated with vibration were collected, and seeded into a new 6-well plate. At the same time, partial samples were stained to evaluate the undifferentiation marker (B) Visualization of relative distances between designed conditions in this work. Four related parameters (acceleration, frequency, amplitude, energy) are visualized by principal component analysis. The proportion of variance for each principal component (PC) is PC1 (0.56), PC2 (0.27), and PC3 (0.16). The loadings are: acceleration: frequency: amplitude: energy = PC1 (−0.04, 0.42, −0.65, −0.64), PC2 (0.89, −0.43, 0.09, 0.13), PC3 (0.46, −0.80, −0.25, −0.30). The color representation is visualized in the legend. Representative four points from tapping and closing of incubator door condition measured in the preliminary examination is visualized with smaller dots to indicate the range of vibration.