Fetch and analyze nucleotide sequences from NCBI database
Back to Tools| Accession ID | Sequence | Organism | Length | Molecule Type | Update Date |
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This tool retrieves records from NCBI by one accession or by a consecutive accession range (shared letter prefix, increasing numeric suffix). Each range request may include at most 25 sequences. Results appear in the preview table; a CSV file downloads when the fetch completes.
GU339067 … GU339071) with end ≥ start. The server expands the span; if it exceeds 25 sequences, narrow the range or split into multiple runs.
Scope: Range mode is for consecutive IDs with a common prefix—not arbitrary lists. Use nucleotide accessions for DNA/RNA; protein IDs return protein sequence. Availability depends on NCBI. For research and teaching, not clinical use.
The Sequence Fetch Tool allows you to retrieve multiple nucleotide sequences from NCBI databases by specifying a range of accession IDs. It's useful for batch downloading sequences for research, comparison, or analysis purposes.
Enter the starting and ending accession IDs to define your sequence range. The tool will fetch all sequences within that range. For example, entering GU339067 to GU339071 will retrieve 5 sequences (GU339067, GU339068, GU339069, GU339070, and GU339071).
You can retrieve organism name, sequence length, molecule type, and update date by checking the corresponding options in the "Additional Fields" section.
Yes, the "Preview Length" dropdown lets you select how many base pairs to display for each sequence, ranging from 50bp to the full sequence. This helps manage loading times when working with very long sequences.
After fetching, a CSV file downloads automatically with accession IDs, sequence columns, and any metadata you selected. You can open the CSV in Excel or import it into other tools; for FASTA, copy the sequence column or convert the file as needed.