The index — the first of its kind — lists and quantifies the complement of proteins expressed in 157 different tissues from a single female donor who died of cardiac arrest. The proteins were identified 'factory-style' by mass spectrometry after being separated in the different tissues by two-dimensional gel electrophoresis.

The index includes over 115,000 different proteins, encoded by an estimated 18,000 different genes. Humans are generally thought to have between 30,000 and 70,000 genes. Large Scale Proteomics — part of the Large Scale Biology Corporation — is expanding the database, using tissues from additional donors, to detect proteins expressed at low levels and to map the cellular and subcellular distribution of proteins.

A Human Proteome Index was conceived in 1980 by Norman Anderson, then at the Oak Ridge National Laboratory in Tennessee, as a large-scale federally funded project, but the idea lost political support. His son, Leigh Anderson, has been the driving force behind the latest effort.