Fig. 2.

The cell viability (A), the live cell recovery rate (B), and the phase-contrast photomicrographs (C) of cryopreserved HEK 293 cells with different freezing solutions (1)–(6). The composition of six freezing solutions was prepared using D-MEM. Solution 1. 1% sericin, 0.1 M maltose, and 10% glycerol; Solution 2. 1% sericin, 0.1 M maltose, and 10% DMSO; Solution 3. 10% FBS, and 10% glycerol; Solution 4. 10% FBS, and 10% DMSO; Solution 5. 10% DMSO; Solution 6. 10% FBS. The data settings were the cell viability (closed column) and the live cell recovery rate (open column). Scale bar: 60 μm. Data are presented as mean ± standard error. Each experiment was repeated in triplicate (n ≥ 3).