Freezing of biological material

A method of freezing human and/or animal cells in suspension, wherein one or more samples of human and/or animal cells in suspension are contained in container(s) including one or more liquids, the method comprising:

• controlling cooling capacity in such a manner that the phase transition time of a sample can be regulated and controlled;
• determining the cooling needed such that the phase transition time of a calibration sample contained in a container is an any more or less precise length below 6 minutes;
• cooling said one or more samples in the same manner as said calibration sample by controlling the amount of cooling, such that that the phase transition time of the sample is regulated to an any more or less precise length below 6 minutes,
• wherein less than 2% of cryoprotectant of the total sample volume is added to the container containing the biological material.