**4. Viability of vitrified-thawed MSCs**

Live/dead viability of MSCs was determined by the trypan blue staining test. The number of MSCs was counted and compared to that of the control. After thawing, the viability rates were 81.33% ± 6.83 for the vitrification method and 80.83% ± 6.4 for the OPS vitrification, while values with the pre-vitrification control group were 88.16% ± 6.3, respectively (Table 1). There were no differences in viability between them.


OPS: open-pulled straw, student t-test (p<0.05).

Table 1. Percentage of cell viability of non-cryopreserved and two different cryopreserved vitrification methods by the trypan blue staining test.
