The invention provides polyamide-oligonucleotide derivatives of the formula: F[(DNA-Li)q(PNA-Li)r(DNA-Li)s(PNA)t]xF′. In the formula, q, r, s, and t are, independently of one another, zero or 1, where the total of two or more adjacent q, r, s, and t is greater than or equal to 2; and x is 1 to 20. In the formula, DNA is a nucleic acid such as DNA or RNA or a known derivative thereof. Li is a covalent linkage between DNA and PNA, where the covalent linkage comprises a bond or an organic radical with at least one atom from the series consisting of C, N, O, or S. PNA is a polyamide structure which contains at least one nucleotide base that is different from thymine. F and F′ are end groups and/or are linked together by a covalent bond. The invention also provides physiologically tolerated salts of the above formula. The invention further provides a process for preparation of the polyamide-oligonucleotide derivatives of the invention as well as their use as pharmaceuticals, as gene probes, and as primers.