Aseptic and automatable vitrification of human embryonic stem cells using defined media

Aseptic and automatable vitrification of human embryonic stem cells using defined media Efficient recovery of biologically safe and undifferentiated hESCs is a major challenge after cryobanking, especially when their use for human therapy is foreseen. One drawback of actual cryopreservation protocols is the direct contact of the cells with liquid nitrogen, therefore cells can be in contact with heavy metals, bacteria, viruses or fungi during cooling and storage. We describe a novel cryopreservation method which uses aseptic vitrification1 (no direct contact with LN2) and only chemically defined materials and media, and is automatable. 1: Vitrification is a cryopreservation method based on the conversion of a liquid into a glass-like state by an infinite enhancement of its viscosity and without formation of ice crystals