There are around 500 public and commercial biological databases. These databases contain information about nucleotid sequences of genes or amino acid sequences of proteins. Furthermore information about function, structure, localisation on chromosome, clinical effects of mutations as well as similarities of biological sequences can be found.

With help of biological databases, the cooperation of biomolecules and the whole metabolism of an organism should be explained. This would facilitate the rational fight against diseases and the development of medical drugs.

The biological knowledge of databases is usually (locally) separated. This makes it difficult to ensure the consistency of information, which sometimes leads to low data quality of biological databases.