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Biotite at PyPI

Python version

Test status

The Biotite Project

Biotite project

Biotite is your Swiss army knife for bioinformatics. Whether you want to identify homologous sequence regions in a protein family or you would like to find disulfide bonds in a protein structure: Biotite has the right tool for you. This package bundles popular tasks in computational molecular biology into a uniform Python library. It can handle a major part of the typical workflow for sequence and biomolecular structure data:

  • Searching and fetching data from biological databases
  • Reading and writing popular sequence/structure file formats
  • Analyzing and editing sequence/structure data
  • Visualizing sequence/structure data
  • Interfacing external applications for further analysis

Biotite internally stores most of the data as NumPy ndarray objects, enabling

  • fast C-accelerated analysis,
  • intuitive usability through NumPy-like indexing syntax,
  • extensibility through direct access of the internal NumPy arrays.

As a result the user can skip writing code for basic functionality (like file parsers) and can focus on what their code makes unique - from small analysis scripts to entire bioinformatics software packages.

If you use Biotite in a scientific publication, please cite:

Kunzmann, P. & Hamacher, K. BMC Bioinformatics (2018) 19:346.


Biotite requires the following packages:

  • numpy
  • requests
  • msgpack
  • networkx

Some functions require some extra packages:

  • mdtraj - Required for trajetory file I/O operations.
  • matplotlib - Required for plotting purposes.

Biotite can be installed via Conda...

$ conda install -c conda-forge biotite

... or pip

$ pip install biotite


Here is a small example that downloads two protein sequences from the NCBI Entrez database and aligns them:

import biotite.sequence.align as align
import as fasta
import biotite.database.entrez as entrez

# Download FASTA file for the sequences of avidin and streptavidin
file_name = entrez.fetch_single_file(
    uids=["CAC34569", "ACL82594"], file_name="sequences.fasta",
    db_name="protein", ret_type="fasta"

# Parse the downloaded FASTA file
# and create 'ProteinSequence' objects from it
fasta_file =
avidin_seq, streptavidin_seq = fasta.get_sequences(fasta_file).values()

# Align sequences using the BLOSUM62 matrix with affine gap penalty
matrix = align.SubstitutionMatrix.std_protein_matrix()
alignments = align.align_optimal(
    avidin_seq, streptavidin_seq, matrix,
    gap_penalty=(-10, -1), terminal_penalty=False



More documentation, including a tutorial, an example gallery and the API reference is available at


Interested in improving Biotite? Have a look at the contribution guidelines. Feel free to join or community chat on Discord.