Kirsten Craven

What do scientists really think about EAD for Met ID?

Jan 8, 2026 | Blogs, Pharma | 0 comments

Read time: 3 minutes

During an LC-MS/MS experiment, traditional fragmentation techniques like collision-induced dissociation (CID) have long been the gold standard. Electron-activated dissociation (EAD) is emerging as a transformative tool that enhances structural elucidation, particularly for complex or labile metabolites.

What is EAD and why does it matter?

EAD is a fragmentation technique used in tandem mass spectrometry (MS/MS) that utilizes high-energy electrons to break molecular ions into fragments. EAD preserves labile bonds and generates rich, diverse fragmentation patterns that complements CID data. This makes it particularly valuable for identifying isomeric metabolites, phase II conjugates, and metabolites with fragile functional groups.

Key advantages of EAD in Met ID

Enhanced structural elucidation
Preservation of labile bonds
Improved confidence in metabolite identification
Complementary to CID

The real test of any analytical technology is in the information it can provide in the real-world. Here are a two examples that that have been published in peer-reviewed publications.

Springer Nature: Streamlined high-throughput data analysis workflow for antibody-drug conjugate biotransformation characterization

Abstract

Research into antibody-drug conjugates (ADCs) is currently at an inflection point due to recent clinical impact. ADC biotransformation analysis is key for understanding the structural integrity of ADCs in vivo and is a critical aspect of drug development, especially at the lead selection stage. Data analysis of biotransformed products is hindered by the manual and time-consuming analyte identification process oftentimes taking days to weeks. We developed a streamlined data analysis workflow enabling more automated peak identification using several commercial software tools that significantly improve data processing efficiency. A linker-payload biotransformation library was created for each new molecule and combined with antibody sequence information for peak matching. As a proof of concept, we tested this workflow across different payload and linker types, acquired using different mass spectrometers: an example using a topoisomerase I inhibitor-conjugated ADC (SCIEX ZenoTOF 7600) and a comparison to a published in vivo ADC biotransformation data set for a pyrrolobenzodiazepine-conjugated ADC (ThermoFisher QE HF-X). Using this more automated workflow, we rapidly identified major biotransformation species that were previously found manually including loss of linker-payload, thiosuccinimide ring hydrolysis, cysteinylation at the deconjugation site(s), and partial linker-payload cleavage. This improved data analysis workflow has demonstrated superb effectiveness in streamlining overall ADC biotransformation identification and enabled quantification that was highly comparable to previously obtained results. Broadening application of advanced analytical techniques to study biotherapeutic biotransformation can now more effectively impact drug development by enabling faster design-test-analyze cycle times, critical in early drug discovery settings opening new avenues for more effective collaboration between analytical chemists and bioconjugate engineers.

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Rapid Communications in Mass Spectrometry: Advancing structural elucidation of conjugation drug metabolites in metabolite profiling with novel electron-activated dissociation

Abstract

This study focuses on the advantage of using the novel electron-activated dissociation (EAD) technology on the QTOF system for structural elucidation of conjugation metabolites. In drug metabolite identification, conceptual “boxes” are generally used to represent potential sites of modifications, which are proposed based on MS/MS data. Electron-activated dissociation (EAD) provides unique fragmentation patterns, potentially allowing for more precise localization of the metabolic modification sites compared to CID, particularly for conjugations.

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Future Outlook

At SCIEX we see pharmaceutical companies continuing to adopt high-resolution, information-rich analytical platforms, EAD is poised to become an enabling option for Met ID workflows. Its ability to provide deeper insights into metabolite structures, especially in challenging scenarios, aligns with the industry’s push toward precision medicine, faster development timelines, and regulatory robustness.

Why SCIEX partners with experts around the world

Innovation in mass spectrometry does not happen in isolation. Some of the most impactful scientific advances emerge from highly specialized research communities – proteomics experts developing new peptide identification workflows, metabolomics researchers curating spectral databases, toxicologists building compound libraries, and biopharma scientists creating novel characterization methods.

Managing ADC characterization: The challenge of turning complexity into confidence

Unlike traditional monoclonal antibodies, ADCs combine an antibody backbone with linker chemistry and a cytotoxic payload. This multi-component architecture introduces overlapping layers of heterogeneity, including drug-to-antibody ratio (DAR) distributions, charge variants, post-translational modifications, and structural changes at both the intact and subunit levels. Across ADC development, these characteristics are considered critical quality attributes that must be characterized, understood, and monitored.

3 reasons ZT Scan DIA is changing the game in metabolomics

For years, metabolomics researchers have faced a frustrating reality: modern high-resolution mass spectrometers can detect tens of thousands of molecular features, yet only a fraction can be confidently identified. The challenge is no longer finding molecules. It is generating the high-quality MS/MS data needed to confidently assign structures and extract meaningful biological insights.

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Kirsten Craven

Kirsten Craven is the Senior Global Marketing Manager for Pharma global strategic marketing at SCIEX. In this role, she manages strategic marketing for the pharmaceutical industry. Kirsten spent the first part of her career working in laboratories across multiple industries before moving into product management, and most recently pharma marketing.

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