Abstract: A cell cryopreservation method including adding a 1 volume % of a composition comprising 0.01 wt % to 20 wt % of a sophorose lipid to cells in a cell culture medium just before or up to 6 hours before cryopreserving the cells; and cryopreserving the cell culture medium, wherein the composition improves cell viability after cryopreservation compared to cells that are cryopreserved with a similar composition that does not contain the sophorose lipid.

Abstract: This composition can be easily added when cryopreserving cells and improves cell viability. 1 volume % of the composition containing 0.01 wt % to 20 wt % of a sophorose lipid is added just before or up to 6 hours before cryopreservation and cells are stored. This composition can improve cryopreservation cell viability as it reduces freezing damage to cells. With this composition, cells can be stored without using DMSO and blood serum. This is a simple and inexpensive storage method as it does not require fine control of the freezing rate during cell cryopreservation.

Abstract: Methods are disclosed of freezing, cryopreserving, and transferring a frozen sheet-shaped cell culture. The method of freezing includes (1) a step of immersing in a cryopreservation solution a sheet-shaped cell culture supported by a mesh-shaped support body; (2) a step of removing the cryopreservation solution adhered to the sheet-shaped cell culture, while keeping the sheet-shaped cell culture supported by the mesh-shaped support body; (3) a step of enclosing the sheet-shaped cell culture in a cold-resistant film, an upper surface and a lower surface of the sheet-shaped cell culture being covered by the mesh-shaped support body; and (4) a step of freezing the sheet-shaped cell culture.