Preparing a Submission

Before submitting to ENA, your study and samples must meet a set of validation requirements. This page covers what needs to be in place.

Study Requirements

The XML registration path enforces a small set of hard checks before it builds any XML. A study must have:

Field	Requirement
Title	Required, non-empty
Description	Required, non-empty
Samples	At least one sample

There is no minimum character count on the title or description, no required unique alias, and no “ready for submission” flag. The study alias defaults to the study’s internal id when none is set.

Sample Requirements

Every sample in the study must have:

Field	Requirement
Tax ID	Required — ENA needs a `TAXON_ID` for every sample
Sample Title	Optional (falls back to the sample id)
Scientific Name	Optional (included when present)
MIxS Metadata	Recommended — checklist fields are passed through as sample attributes

The only sample field the registration path rejects on is a missing or empty taxId; it reports how many samples are affected.

Tax ID

The taxonomy ID is the most common source of validation errors. Every sample must have a valid NCBI taxonomy ID:

For species samples: use the species-level tax ID
For metagenomes: use the appropriate metagenome identifier (e.g., 408170 for human gut metagenome)

See Organism & Taxonomy for common identifiers.

MIxS Fields

Checklist fields you fill in SeqDesk are mapped to ENA’s expected attribute names and passed through as SAMPLE_ATTRIBUTE entries. Common MIxS fields:

Geographic location (country and/or sea)
Geographic coordinates (latitude, longitude)
Collection date
Environmental context (broad-scale and local)
Environmental medium

Validation Checklist

Before submission, verify:

Study has a non-empty title and description
The study has at least one sample
Every sample has a valid taxonomy ID
Required MIxS fields are filled for the selected checklist (these become sample attributes)
ENA credentials are configured (see ENA Credentials)

Common Validation Issues

Issue	Solution
Missing tax ID	Use the organism autocomplete to search NCBI taxonomy
Invalid tax ID	Verify the ID at NCBI Taxonomy website
Missing required MIxS fields	Check the checklist requirements and fill all mandatory fields
Study has no samples	Add at least one sample before registering

Test Mode

Always start with test mode enabled:

Configure ENA credentials in Admin → ENA Configuration
Enable Test Mode (uses wwwdev.ebi.ac.uk instead of production)
Submit to the test server to validate everything
Test submissions expire after 24 hours on ENA’s side
Once validated, disable test mode and submit to production