Abstract: The invention relates to a method for introducing common and/or individual sequence elements in a target nucleic acid molecule in a sample containing sample nucleic acid molecules, comprising the steps: i) denaturing the sample nucleic acid molecules, if the sample nucleic acid molecules are double-stranded, to obtain single stranded sample nucleic acid molecules; ii) bringing the sample nucleic acid molecules in contact with primary, secondary and tertiary probe nucleic acid molecules, wherein the 3?-end of the tertiary probe comprise a part complementary to the primary probe and the 5?-end of the tertiary probe comprise a part complementary to a 5?-part of the target nucleic acid molecule; the 3?-end of the secondary probe is complementary to a 3?-part of the target nucleic acid molecule and the 5?-end of the secondary probe is not complementary to the target nucleic acid molecule; wherein said primary, secondary and tertiary probes comprise said common and/or individual sequence elements; iii) ligating the