Fig. 1

Fluorescence images of MSCs recovered from cryopreservation at –196 °C for 7 days, without post-thaw culture (a) and with 24 h post-thaw culture at 37 °C (b). The scale bar is 100 µm. PEGs as cryoprotectants varied their molecular weight over 400, 600, 1 K, 1.5 K, 5 K, 10 K, and 20 K Da at a concentration 10 wt.%. 0 h, 2 h, and 4 h indicate preincubation time of MSCs in the presence of PEGs at 37 °C before cryopreservation. c) Quantitative analysis of cell recovery for the post-thaw culture systems at 37 °C for 24 h. ** indicates p < 0.01. N = 3