Abstract: A method is provided for spectroscopic real-time detection of nucleic acid molecules, in particular polynucleotide sequences, in a PCR amplification (PCR=polymerase chain reaction). The PCR amplification process includes preparing the initial substances required for producing a PCR solution in a buffer, and the repeating PCR reaction steps of denaturing, primer hybridization and elongation. Electromagnetic radiation is irradiated into the PCR solution during the PCR amplification at defined time points from a radiation source in the gigahertz or terahertz regime in order to detect at least the presence or absence of a polynucleotide sequence using a detector in a real-time detection.