For many applications within the life sciences a cell separation or cell purification step is needed. Most techniques are based on binding cells to a substrate surface and then detaching selected cells, e.g. by protein-digesting enzymes. However, these techniques can damage the cells or lead to the spontaneous alteration of cells, such as differentiation of undifferentiated cells.

Further techniques for cell separation or purification, especially in the field of stem cell cultivation, are based on magnetic particles or include chemical agents. However, each of these methods have their own disadvantages, e.g. being complex/expensive and/or being harmful to the cells.

In the last years, polymer-based coatings have come into focus. However, these methods do not provide for separation of cells at different stages, or, if they do, cell separation is not sufficiently selective or only feasible with time-comsuming, expensive or cell damaging methods. In addition, these polymer-based methods may rely on monomers, which are not sufficiently biocompatible, even toxic.

The present technology overcomes these limitations and provides an extremely mild, non-invasive, highly selective, straightforward and cost-effective tool to not only separate different cell types, but also cells at various differention stages.

The technology is based on a biocompatible stimulus-responsive polymer layer. By applying a temperature shift, different cell populations bound to that layer are selectively separated depending on their specific binding properties during the different phases of the method. The method is inter alia highly suited for isolating iPS cells and stem cells at different stages.