The method involves placing an oocyte cell in a cell holder (1), securing the cell holder in a treatment station, applying a treatment solution to the cell by washing the cell with the solution, and rapidly cooling the cell holder and cell to a predetermined cryopreservation temperature for cryopreservation of the cell. The cell is cooled at a high rate sufficient to permit vitrification of the cell and any surrounding treatment solution to occur. The cell is then maintained at or below a predetermined storage temperature for storage. The method allows multiple cells to be treated simultaneously each secured within a respective cell holder.