The invention describes a foil of polymeric material comprising a plurality of patch portions and a grid portion arranged between said patches. Each patch portion is connected to the grid portion by means of one or more connecting elements. Each patch portion is separated from the grid portion in the X-Y plane by means of a release portion, said release portion having a tensile strength in the X-Y plane which is lower than the tensile strength of both said patch portions and said grid portion, such that—upon exertion of a tensile force between said patch portions and said grid portion—said foil ruptures preferentially at said release portion. The invention relates to a method for the production of cell-capture chips using said foil, and a cell capture chip produced by said method.