Between 1990 and 2003, Human Genome Project undertook the immense task of sequencing the 3 billion bases of genetic information that reside in every human cell.

The Human Genome Project, which began officially in 1990, was the largest international collaboration ever undertaken in biology and involved thousands of scientists.

The sequencing of the 3 billion bases of DNA in the human genome will allow researchers to identify human genes, assisting our understanding of the genetic basis of disease and of the key biochemical and developmental processes of the human body.

The project was undertaken by the Wellcome Trust Sanger Institute in the UK, US laboratories funded by the National Human Genome Research Institute (NHGRI) and the US Department of Energy, and several other centres worldwide.

Background: The Human Genome Sequencing Consortium

Having begun in earnest in 1995, the programme announced a working draft of 90 per cent of the human genome in June 2000. The 'working draft' provided invaluable information for biomedical researchers and acted as the foundations on which the finished genome is built.

Feature: History of the Human Genome Project

In February 2001, the Consortium published an initial analysis of the human genome. The most surprising discovery was that humans have only about 30 000 genes – many people had expected humans to have about 100 000 genes.

The final, high-quality human genome sequence was completed in 2003. This is the 'gold standard' reference sequence that researchers will use for decades to come. The analysis of the final sequence, published in October 2004, reduced the human gene number to 20-25 000.

News: Finished human genome contains even fewer genes than expected

The Sanger Institute sequenced one-third of the human genome, focusing on chromosomes 1, 6, 9, 10, 13, 20, 22 and X (some of which were shared with other centres).

Links: Wellcome Trust Sanger Institute: Human Genome Project