DNA stands for deoxyribonucleic acid. Strands of DNA are long polymers composed of millions of nucleotides linked together. The sequence of nucleotides determines individual hereditary characteristics (the fingerprint) for all living matter, including grape vines. DNA fingerprinting (also called DNA profiling or DNA typing) allows small tissue samples of various grape VARIETIES to be compared and analyzed to determine if they are similar or identical. In the United States, UNIVERSITY OF CALIFORNIA, DAVIS researchers have been at the forefront of DNA profiling. In the early 1990s, Davis researchers used DNA fingerprinting to establish a relationship between California’s ZINFANDEL and Italy’s Primitivo. They established that some (but not all) examples of Primitivo were identical to Zinfandel, which caused speculation that Zinfandel might have originated in Italy. However, in late 2001, through collaborative efforts of researchers at UC Davis and the University of Zagreb in Croatia, DNA analysis determined that Crljenak (a little-known grape from Croatia) and Zinfandel had identical DNA profiles. Further analysis proved that a more popular Croatian grape, Plavac Mali, was a descendant of Crljenak (and therefore of Zinfandel). In 1997 researchers at UC Davis determined that CABERNET SAUVIGNON is an offspring of SAUVIGNON BLANC and CABERNET FRANC. Since Cabernet Sauvignon appeared in the late seventeenth century prior to plant hybridization practices, UC Davis scientists believe that its origin was a natural occurrence rather than a planned CROSS of the two parents. This serendipitous union turned out to be viticulturally historical. Based on DNA profiling, Chardonnay’s origins are believed to be from the Pinot family (PINOT NOIR, PINOT GRIS, PINOT BLANC) on one side and from Gouais Blanc (a mediocre variety) on the other. Gouais Blanc, which is no longer grown in France, appears to be identical to Heunischweiss, a variety once widely grown in eastern Europe. Information on these varieties has been added to the DNA profiles of about 700 grape varieties, a database developed in collaboration with UC Davis researchers’ colleagues in Montpellier, France. These profiles will contribute to the efforts of the International Grape Genome Project—groups of research teams in ten countries that map the genetic material of grapes to better understand various characteristics of grapes.