Protocol for the quantification of melatonin and AFMK in cerebrospinal fluid by LC-MS/MS
Melatonin and its oxidant derivative, N-acetyl-N-formyl-5-methoxykynuramine (AFMK), are indolamines present in higher organisms, which are related to light-darkness circadian rhythms and redox physiology. Here, we present a protocol for the quantification of both in cerebrospinal fluid (CSF). We describe steps for standardization by isotopic dilution or alternatively by internal standard 5-methoxytryptophol (5-MT). We then detail procedures for quantification by using liquid chromatography coupled to tandem mass spectrometry. For complete details on the use and execution of this protocol, please refer to Artime-Naveda et al.<sup>1</sup>.
Authors
- Juan Carlos Mayo (ORCID: https://orcid.org/0000-0002-0882-2047)
- Francisco Artime-Naveda (ORCID: https://orcid.org/0000-0001-5141-4404)
- Pablo Rodríguez‐González (ORCID: https://orcid.org/0000-0001-9317-8833)
- Adriana González‐Gago (ORCID: https://orcid.org/0000-0002-6531-4620)
- Rosa María Sainz (ORCID: https://orcid.org/0000-0003-3048-5582)
- Anna Zawadzka (ORCID: https://orcid.org/0000-0003-0971-6550)
- David Hevia-Sánchez
Institutions
- Universidad de Oviedo (ES)
- Instituto de Investigación Sanitaria del Principado de Asturias (ES)
- University of Warsaw (PL)
Publication Details
- Journal
- STAR Protocols
- Published
- 2025-10-23
- DOI
- https://doi.org/10.1016/j.xpro.2025.104145
- Primary Topic
- Circadian rhythm and melatonin
- Type
- article
- Field-Weighted Citation Impact
- 0.00