Shipment of Frozen Cells

Cultured cells are shipped frozen in medium plus 10% DMSO. Cells can be kept for short periods (<1 week) at -70°C or can be transferred to liquid nitrogen for longer periods (years). Once thawed, the cells cannot be refrozen and must be transferred to culture dishes immediately.

For cultivation of cells shipped in screw-cap vials, thaw cells rapidly in a 37°C water bath being careful not to contaminate the cap/vial junction area with water. Prior to opening the vial, wipe the outside with 70% ethanol:30% water to remove/kill any contaminants. As soon as the cells have thawed, pipet gently to suspend cells and dilute at least 10-fold with culture medium (DMEM with 4.5 g/l glucose plus 10% FBS, 10 ml or more) prior to seeding into culture dishes. Replace medium after cells have attached (can leave overnight). Centrifugation to remove DMSO prior to seeding is not recommended as this procedure often leads to more cell death.

For cells shipped in glass vials, the vials are prescored for easy opening. Thaw by direct immersion in a 37°C water bath. Immediately after cells thaw, wipe the outside of the vial with 70% ethanol:30% water and snap off the top of the vial. Use sterile gauze pads to protect your hands from possible glass shattering and to protect the sterility of the contents. Pipet cells gently to suspend and seed into culture dishes as described above.

Multiple vials of cells should be refrozen as soon as possible after initial cell cultivation. The properties of some cell types change with time of culture (e.g., retrovirus packaging cells) and cultures can become contaminated with other organisms, thus it is important to preserve early cultures of the cells.