A method is disclosed for reliably stabilizing eukaryotic cells that express the P2X.sub.7 receptor channel, particularly mammalian and other vertebrate cells, including human cells, for example mammalian macrophages, or hematopoietic stem cells, in order to introduce otherwise membrane-impermeable compounds that are helpful for stabilizing the cells during drying, chilling, freezing, freeze-drying, or cryopreservation. The cells are exposed to extracellular ATP in concentration sufficient to open pores in the plasma membrane. One or more otherwise membrane-impermeable compounds that aid the survivorship of cells are then introduced, for example, trehalose, and after a brief time the pores are closed--for example, by adding divalent cations, or by diluting the extracellular solution. Once the trehalose or other stabilizing compound has been introduced, the cells may be stably preserved. By taking advantage of an endogenous mammalian receptor and ATP, no antigenic compounds need be introduced.