The invention relates to a process for cultivating undifferentiated stem cells in suspension and in particular to a method for cultivating stem cells on microcarriers in vessels. The method enables stem cells to be cultivated in a scalable process for the first time, without losing their pluripotentiality. Different types of vessels are suitable for cultivation, such as e.g. spinners and bioreactors. The option of precisely setting the cultivation conditions in said vessels aids the process of obtaining a pluripotentiality of the stem cells. the inventive method also permits large yields of stem cells of an unvarying quality to be produced.
