The present invention relates to a method for introducing mutations into at least one target nucleic acid molecule comprising (a) providing at least one sample comprising at least one target nucleic acid molecule; and (b) amplifying the at least one target nucleic acid molecule using a low bias DNA polymerase. The present further relates to a use of a low bias DNA polymerase in a method for introducing mutations into one or more nucleic acid molecule(s), a group of sample tags, a method for designing the group of sample tags, a computer readable medium, and a method for preferentially amplifying target nucleic acid molecules.