Genomics · Database
European Nucleotide Archive
EMBL-EBI's repository of raw sequencing reads, genome assemblies, and annotated nucleotide sequences.
What European Nucleotide Archive is
The European Nucleotide Archive (ENA) is a public repository maintained by the European Bioinformatics Institute (EMBL-EBI) that provides unrestricted access to annotated DNA and RNA sequences, raw sequencing reads, assemblies, and associated study and sample metadata. Originating from the EMBL Data Library established in 1980, the archive serves as a central resource for molecular biologists and genomic researchers needing nucleotide sequence information.
ENA is composed of three primary databases: the Sequence Read Archive (SRA), the Trace Archive, and the EMBL Nucleotide Sequence Database (EMBL-Bank). Together with the DNA Data Bank of Japan (DDBJ) and GenBank, ENA is a member of the International Nucleotide Sequence Database Collaboration (INSDC), exchanging submitted sequencing data with these partner databases on a daily basis.
How it is organised
The repository ingests and manages data across three distinct tiers. Raw sequence reads and analyses from high-throughput sequencing technologies are handled by the Sequence Read Archive, predominantly using BAM format and the NCBI SRA Toolkit for compression and conversion to formats like FASTQ. Earlier capillary reads are archived in the Trace Archive. Higher-level assembled contigs, full genomes, and functional annotations are stored in the EMBL Nucleotide Sequence Database using a dedicated flat-file plaintext structure known as EMBL-Bank format.
Users can query and retrieve records through the ENA browser, programmatically via REST and SOAP APIs, or through text queries powered by the EB-eye search engine. The archive also supports sequence similarity searching implemented using De Bruijn graphs, and exports data in formats such as FASTA, FASTQ, XML, and HTML. To manage storage demands, reference-based compression via the CRAM toolkit is used alongside the selective removal of less-valuable sequencing platform data.
Key facts
- Maintainer
- European Bioinformatics Institute (EMBL-EBI)
- Collaborative network
- International Nucleotide Sequence Database Collaboration (INSDC)
- Component databases
- Sequence Read Archive (SRA), Trace Archive, EMBL Nucleotide Sequence Database (EMBL-Bank)
- Core record types
- Raw sequencing reads, genome assemblies, and annotated sequences
- Supported formats
- EMBL-Bank flat file, BAM, FASTQ, FASTA, XML, HTML
- Data access methods
- ENA browser, REST URLs, EBI SOAP and REST APIs, EB-eye search engine
What you can use it for
- Raw sequencing data retrieval
- Researchers can download raw reads and alignments from next-generation sequencing platforms in BAM or FASTQ formats for secondary bioinformatic analyses.
- Genome assembly and annotation analysis
- Scientists can access fully assembled genomes, contigs, and coding sequence annotations submitted by genome consortia and research groups.
- Transcriptomic data exploration
- Users can examine complementary DNA records and expressed sequence tags along with their corresponding sample metadata.
- Sequence similarity searching
- Computational biologists can run similarity-based queries against archived records using De Bruijn graph implementations.
Query it here
The research agent queries European Nucleotide Archive directly — no account, no API key — and every answer links back to the record it came from. Ask in plain language and it writes the query.
Strengths and limits
Good at
- It provides unified coverage across the full lifecycle of sequence data, from raw reads to fully assembled and annotated genomes.
- Daily automated data exchange with GenBank and DDBJ ensures global synchronization across INSDC partner archives.
- Multiple programmatic access options are available, including REST and SOAP APIs as well as direct REST URL querying via the ENA browser.
Watch out for
- Rapidly expanding storage requirements have necessitated the selective discarding of less-valuable sequencing platform data.
- Its EMBL-Bank flat-file syntax differs from the native record formats used by INSDC partners GenBank and DDBJ.
Questions
Can I search European Nucleotide Archive without writing code?
Yes. The research agent queries European Nucleotide Archive directly, with no account or API key, and cites the record behind every answer. Ask in plain language — for a gene, a protein, a compound or a study — and it builds the query for you.
Can I reuse data from European Nucleotide Archive?
No restrictions on use under the INSDC policy; submitters may assert rights in some records. Reads are fetched from ENA as submitted. Cite the run accessions and the study that produced them. Terms: https://www.ebi.ac.uk/ena/browser/about/policies
What is the difference between the ENA and the Sequence Read Archive?
The Sequence Read Archive (SRA) is one of the three main component databases within the ENA, specifically dedicated to storing raw high-throughput sequence reads and alignments.
How frequently is data synchronized with GenBank and DDBJ?
As part of the International Nucleotide Sequence Database Collaboration, the ENA exchanges data submissions daily with both GenBank and the DNA Data Bank of Japan.
What file formats can be downloaded from the ENA?
Depending on the component database, data can be retrieved in formats including FASTA, FASTQ, BAM, XML, HTML, and EMBL-Bank flat-file format.
Written from European Nucleotide Archive's own website and reference material. Statements citing a figure that does not appear there are removed before publication. Licence and running details come from our registry.