Researchers at the Helmholtz Zentrum München (Neuherberg, Germany) have developed a new MALDI mass spectrometry (MS) technique for the analysis of fixed tissue samples. The new technique enables researchers to analyze hundreds of metabolites in a fixed sample, which could provide new potential for medical diagnostics and research.
Previous assumptions indicated that, unlike DNA and protein analysis, metabolic analysis would not be possible in fixed tissue samples. However, in this new study, published in Nature Protocols, the team have developed a novel MS technique that makes analysis of metabolites possible.
The new protocol utilizes a MALDI-FT-ICR-MSI platform and requires only a small tissue sample in order to determine metabolite composition, returning results within a day. First author Achim Buck (Helmholtz Zentrum München) explained: “Our method permits the analysis of minute biopsies and even tissue micro-arrays, making it particularly interesting for molecular research and diagnostics.”
The team validated their method and data by comparing them to values measured from a sample that was shock frozen rather than fixed, ensuring that the fixing process did not falsify data. “A large proportion of the measured metabolites occurred in both analyses,” reported Buck. “We were able to show that the method works reliably and avoids the complex logistics and storage of shock-frozen samples.”
The new MS method provides simple handling, high reproducibility and the capability for high throughput sample analysis. Furthermore, it permits study of the precise spatial distribution of molecules within the tissue.
“That is an enormous advantage, both in research and in clinical diagnostic practice,” commented project leader, Axel Karl Walch (Helmholtz Zentrum München). “Using our new analytical method, our aim is now to identify new predictive, diagnostic and prognostic markers in tissues, as well as to understand disease processes.”
Sources: Ly A, Buck A, Balluff B et al. High-mass-resolution MALDI mass spectrometry imaging of metabolites from formalin-fixed paraffin-embedded tissue. Nat. Protoc. doi:10.1038/nprot.2016.081 (2016) (Epub ahead of print); www.helmholtz-muenchen.de/en/news/latest-news/press-information-news/article/35346/index.html