The stem cell (1) includes a cellular DNA (2) comprising a plurality of sequences coding different genes and promoters allowing DNA-protein-interactions, at least one protein molecule (3) generated by means of a specific stimulus (12) and at least one DNA-molecule (6) artificially introduced into the stem cell (1). The artificially introduced DNA-molecule (6) comprises at least one binding site sequence (30) being apt to interact with the protein molecule (3), at least one DNA-sequence (40) coding an indicator molecule (5) and at least one minimal promoter sequence (50), allowing the gene expression of said indicator molecule (5), whereby the stem cell further includes at least one indicator molecule (5) having properties allowing its identification and is produced by synthesis of the DNA-sequence (40) coding an indicator molecule (5) of the artificially introduced DNA-molecule (6).
