Introducing Entrez

Most people are familiar with PubMed, but I wonder how many know about the extremely rich databases, that along with PubMed, make up the Entrez system.

Created by the National Center for Biotechnology Information (NCBI) in 1991, Entrez began as a system that contained three "nodes", one for published articles (MEDLINE, later called PubMed), a nucleotide database and a protein database. Today, Entrez is made up of more than 20 nodes or databases. Each node represents specific data objects of the same type, e.g., protein sequences.

What makes Entrez such a robust search system is that it integrates the biomedical literature, DNA and protein sequence databases, 3D protein structure and protein domain data, population study datasets, expression data, assemblies of complete genomes, and taxonomic information into a tightly interlinked system. THIS IS VERY POWERFUL STUFF! These links allow you to search in one of the nodes or databases and link to related information in the other databases.

The image above is a thumbnail of an interactive graphic that demonstrates the rich linking between the Entrez nodes. Check it out on the Model of Entrez Databases page . Place your mouse on one of the nodes and it will show the various links to other databases, including how many records are linked from each resource. Very cool.

For a more in-depth description of the Entrez search and retrieval system, visit the Entrez information pages from NCBI.

Posted by Judy Spak, guest blogger. Stay tuned for more Entrez posts coming soon.