[DNA, 50 years of the double helix: from the concept of molecular hybridization to microarrays].

The discovery of the double helix structure of DNA 50 years ago by J.D. Watson and F.H.C. Crick laid the foundation for modern molecular biology. This opened the way of 50 years of research resulting in the elucidation of gene expression mechanisms, in the development of molecular biology tools allowing analyzing and manipulating genes and in medical and forensic applications now routinely used. The discovery of the double helix structure allowed to evidence the DNA property of molecular hybridization on which are based most of the molecular biology tools, from the old Southern blot method to the recently developed microarrays.