Abstract: The present invention describes methods, carriers, and vectors relating to nucleic acids for labelling an item, wherein each carrier comprises at least 2 nucleotide barcode nucleic acids, other than sample nucleic acid, for labelling, wherein each nucleotide barcode nucleic acid comprises a different minimal nucleotide barcode sequence with a length of at least 4 nucleotides, where at least two of said different nucleotide barcode nucleic acids have a minimal nucleotide barcode sequence of the same length, wherein the combination of these different nucleotide barcode nucleic acids generates a transferable molecular identification barcode, whereby each such transferable molecular identification barcode is different for each of the carriers in the collection.