Reverse spectral search

Chimeric spectra are ubiquitous in MS/MS data, which compromises the quality and reliability of MS/MS matching-based metabolite annotation. Reverse spectral search is a simple yet overlooked solution to chimeric spectra.

Here, we enhanced the reverse search by introducing a penalty factor to unmatched peaks, which increases the number of spectral matches while maintaining rigorous quality control.

Symmetric & reverse spectral search

• Cosine similarity: cosine.py
• Entropy similarity: entropy.py
• Bhattacharyya angle: bhattacharya1.py

Analysis codes

• Chimeric spectra analysis of public datasets: analyze_chimeric_spec.py
• Annotation codes: annotation folder

Citation

Our paper:

Shipei Xing, Vincent Charron-Lamoureux, Haoqi Nina Zhao, Yasin El Abiead, Mingxun Wang, Pieter C. Dorrestein. Reverse Spectral Search Reimagined: A Simple but Overlooked Solution for Chimeric Spectral Annotation. Analytical Chemistry, 2025.

If you use the code from this repository, please cite:

Shipei Xing. Reverse spectral search. GitHub repository, 2024. URL: https://github.com/Philipbear/reverse_search

License

This project is licensed under the Apache 2.0 License (Copyright 2024 Shipei Xing).