Abbreviation for "Polymerase Chain Reaction". It is used in biological and medical laboratories for a variety of different tasks, for example for the detection of hereditary diseases and viral infections, the creation and verification of genetic fingerprints (as part of criminal investigations), the cloning of genes and for parentage tests (paternity tests). The method was invented in 1983 by the American biochemist Kary Mullis (*1944), who was awarded the Nobel Prize in Chemistry in 1993. It involves artificially amplifying a short, precisely defined part of a DNA strand (gene or just part of a gene) with the help of an enzyme called DNA polymerase. In the context of viticulture, molecular genetic analyses are used to determine the origin or identity of grape varieties. It can also be used to detect various vine diseases caused by viruses. Further test procedures are ELISA and indexing.