Fig. 6

a Fluorescence images exhibiting proliferation of MSCs recovered from cryopreservation at –196 °C for 7 days. PEG 400* and PEG 600* indicate that the recovered cells had been preincubated for 2 h at 37 °C before cryopreservation. DMSO indicates the traditional system using DMSO 10% for cryopreservation of MSCs. The scale bar is 100 μm. b Quantitative analysis of cell proliferation relative to day 0 (100%) assayed by the CCK-8