The Human Genome Project was a 13-year collaborative international project that was completed in 2003. It had the goals of identifying all the approximately 20,000-25,000 genes of the human DNA, determining the sequences of the chemical base pairs that make up human DNA, and storing this information in databases. The project used both hierarchical shotgun sequencing and whole genome shotgun sequencing techniques, as well as the Sanger dideoxy chain termination method, to fully map the human genome. The project raised several ethical, legal and social issues regarding privacy and use of genetic information.