Antibody & Biologics · Oxford Protein Informatics Group
ANARCI
Numbers antibody sequences and annotates framework and CDR regions across multiple numbering schemes.
What ANARCI is
ANARCI is an antibody sequence annotation tool developed by the Oxford Protein Informatics Group. It serves as an initial preprocessing step in antibody analysis workflows by assigning standard numbering schemes to an antibody chain sequence.
The tool parses the input sequence to identify and demarcate framework regions and complementarity-determining regions (CDRs). Standardising residue positions ensures downstream antibody analysis and modelling tools reference structurally consistent positions across different sequences.
Key facts
- Version
- 2021.02
- Domain
- Antibody
- Tasks
- Annotation, numbering
- Input modality
- Protein sequence
- Hardware requirement
- CPU-only
What you can use it for
- Antibody sequence numbering
- Apply standardised numbering systems, including Chothia, IMGT, and Kabat, to raw antibody chain sequences.
- Framework and CDR boundary annotation
- Delimit framework regions and complementarity-determining regions to generate tabular outputs of numbered residues for downstream analytical pipelines.
Run it here
No installation and no GPU of your own: fill in the inputs and it runs on our servers. Results stay in your browser unless you sign in.
Runs on On-demand CPU
Runs on our servers with on-demand compute. A first run needs time to load the model; active capacity can be reused and scales down when idle.Run this model
ANARCI
Strengths and limits
Good at
- Runs entirely on CPU without requiring specialised hardware.
- Executes effectively instantaneously to support rapid sequence preprocessing.
- Accommodates major antibody numbering conventions including Chothia, IMGT, and Kabat.
Watch out for
- Requires selecting a specific supported numbering scheme rather than automatically inferring one.
- Operates exclusively on protein sequences rather than three-dimensional structural coordinates.
Inputs and outputs
You provide
Antibody chain
Single-letter amino acid code. Whitespace and FASTA headers are stripped automatically.
Numbering schemeoptional
You get back
Numbered residues with framework/CDR assignment.
Licence
Commercial use permitted · BSD-3-Clause
The BSD-3-Clause licence allows use in commercial research and products.
Questions
Can I use ANARCI commercially?
Commercial use permitted. The BSD-3-Clause licence allows use in commercial research and products.
How do I run ANARCI without installing anything?
Use the form under “Run it here” on this page: fill in the inputs and press Run model. It runs on our servers, typically in 200ms, and a run costs free. Visitors without an account get 1,000 credits a month.
What inputs does ANARCI require?
It takes an antibody chain protein sequence and a chosen numbering scheme.
Which numbering schemes are supported?
It supports standard schemes including Chothia, IMGT, and Kabat.
What format does the output take?
It outputs a table containing the numbered residues alongside framework and CDR region assignments.
What hardware is required to run ANARCI?
It runs entirely on standard CPU hardware.
Written from ANARCI's own documentation. Statements citing a figure that does not appear there are removed before publication. Licence and running details come from our registry.