The invention is directed to a method for the preparation of a cell population from a sample originating from bone marrow or blood, comprising the steps a) dividing the sample into a first fraction containing 50 to 99% of the cells of the sample and a second fraction containing 50 to 1% of the cells of the sample, b) labeling the cells of the first fraction with a first marker against TCR alpha/beta, c) labeling the cells of the second fraction with a second marker against CD45RA, d) removing the labeled cells from the first and second fraction and combining the remaining cells to a cell population. Furthermore, the invention is directed to a cell composition and the use of the cell composition
