Patent ID: 7314755

Claim:
A method for preserving vertebrate cells, said method comprising the steps of: (a) treating the vertebrate cells with a free extracellular agent comprising adenosine 5′-triphosphate or comprising 2′,3′-O-(benzoyl-4-benzoyl)-adenosine 5′-triphosphate, at a pH from about 6.0 to about 9.0; wherein the membranes of the cells comprise receptors that, in response to a sufficient concentration of the extracellular agent, cause the opening of pores in the membranes; and wherein the concentration of the extracellular agent is sufficient to cause the receptors to open pores in the membranes; whereby pores are opened in the membranes that would not be open in the absence of the extracellular agent; (b) exposing the cells to a preservative; wherein the preservative crosses the cell membrane substantially faster while the pores are open than the preservative would cross the cell membrane under otherwise identical conditions without the opened pores; and wherein the preservative enhances viability if the cells are subsequently dehydrated, frozen, or freeze-dried; (c) closing the pores by reducing the concentration of the free extracellular agent, wherein the pores are closed sufficiently soon after step (a) to maintain the viability of a substantial fraction of the cells; and (d) dehydrating the cells, freezing the cells, or freeze-drying the cells; wherein the viability of the cells, if subsequently reconstituted or warmed, is substantially greater than would be the viability of otherwise identical cells that had not been subjected to said steps (a) through (d) prior to being dehydrated, frozen, or freeze-dried; wherein: steps (a) and (b) may be conducted in either order, or steps (a) and (b) may be conducted simultaneously; provided that steps (a) and (b) overlap for a period of time sufficient for enough of the preservative to cross the cell membranes to enhance viability if the cells are subsequently dehydrated, frozen, or freeze-dried; and steps (a) and (b) substantially precede step (c); and step (c) substantially precedes step (d); and said vertebrate cells comprise nucleated cells or erythrocytes.