Method of freezing cells and cell-like materials

A process for freezing cells, cell membranes or cell-like materials comprising the steps of:

• freezing an aqueous mixture comprising a plurality of cells, cell membranes or cell-like materials with a cryoprotective component;
• wherein said frozen aqueous mixture is characterized by a glass transition temperature of above about -60.degree. C.;
• said cryoprotective component containing a saccharide capable of permeating and stabilizing said cells, membranes or cell-like materials;
• and a second water-soluble compound impermeable to said cells, cell membranes or cell-like materials;
• the amount of said second compound in said mixture being in a weight fraction sufficient to overcome the predicted depression in said glass transition temperature of said mixture due to said first compound;
• and
• wherein said freezing is performed by lowering the temperature of said mixture to a temperature at, or below said glass transition temperature of said mixture and above the glass transition temperature of water to form a frozen mixture.