Abstract
Carboxylated poly-L-lysine that is one of the polyampholytes, has good cryoprotective properties as
a novel cryoprotectant. However, the mechanism is unknown. We investigated whether the
polyampholytes could suppresses osmotic damage into cells at a high osmotic pressure condition
that mimics freeze concentration. It was found that polyampholytes reduced dehydration stress
when frozen at high osmotic pressure. Furthermore, by comparing the cell size at the time of
freezing, it was suggested that the polyampholytes might promote cell dehydration and protect the
cell membrane.
