Method for the in vitro selection of at least one therapeutic cell subpopulation from an original cell population, wherein the original cell population is selected from mesenchymal stem cells and astroglia, wherein the therapeutic cell subpopulation can be used for the treatment of diseases of tissues or organs, and wherein the method has the following steps: a) Addition of an original cell population to a first starting reservoir, which is connected via at least one selection means (18;19) having at least one opening (19; 29) to at least one second selection reservoir (12, 13, 14, 15, 16, 17; 30), wherein the at least one opening (18; 29) of the at least one selection means (18; 19) has a diameter of 8 μm to 12 μm; b) Addition of at least one cell culture medium to the at least one selection reservoir (12, 13, 14, 15, 16, 17; 30) to which the therapeutic cell subpopulation migrates, wherein the cell culture medium is a cell type-specific culture medium without specific additives that can influence the growth or differentiation, activation, and migration/chemotaxis of the cells; c) Culturing of the original cell population for a period of 15 min to 6 hours, within which period a cell subpopulation migrates through the at least one opening (19; 29) of the selection means (18; 19) towards the at least one selection reservoir (12, 13, 14, 15, 16, 17; 30); d) Selection and obtaining of a cell, which is selected from at least one of the cells that have migrated, within the first thirty minutes, as the first to the one hundredth cell through the at least one opening (19; 29) of the selection means (18; 19) into the at least one selection reservoir (12, 13, 14, 15, 16, 17; 30), in order to obtain a cell subpopulation with an elevated migration potential as compared to the original cell population. a) Addition of an original cell population to a first starting reservoir, which is connected via at least one selection means (18;19) having at least one opening (19; 29) to at least one second selection reservoir (12, 13, 14, 15, 16, 17; 30), wherein the at least one opening (18; 29) of the at least one selection means (18; 19) has a diameter of 8 μm to 12 μm; b) Addition of at least one cell culture medium to the at least one selection reservoir (12, 13, 14, 15, 16, 17; 30) to which the therapeutic cell subpopulation migrates, wherein the cell culture medium is a cell type-specific culture medium without specific additives that can influence the growth or differentiation, activation, and migration/chemotaxis of the cells; c) Culturing of the original cell population for a period of 15 min to 6 hours, within which period a cell subpopulation migrates through the at least one opening (19; 29) of the selection means (18; 19) towards the at least one selection reservoir (12, 13, 14, 15, 16, 17; 30); d) Selection and obtaining of a cell, which is selected from at least one of the cells that have migrated, within the first thirty minutes, as the first to the one hundredth cell through the at least one opening (19; 29) of the selection means (18; 19) into the at least one selection reservoir (12, 13, 14, 15, 16, 17; 30), in order to obtain a cell subpopulation with an elevated migration potential as compared to the original cell population.