Detecting ferroptotic cells using an antibody against hyperoxidized PRDX3.

Ferroptosis is a regulated form of cell death driven by iron-dependent lipid peroxidation. Although its biological and clinical relevance is increasingly clear, routine and specific detection of ferroptosis remains challenging, especially in tissues and clinical specimens. Indirect measurements of ferroptosis such as lipophilic fluorescent probes (C11-BODIPY581/591), reactive aldehydes (MDA/4-HNE), and pharmacological rescue either lack specificity for ferroptosis, or are impractical for in vivo analysis. Recent work has identified hyperoxidized peroxiredoxin 3 (PRDX3), also known as SO2/3-PRDX3, as a ferroptosis-specific biomarker: Under ferroptotic stress, mitochondrial PRDX3 undergoes selective and irreversible hyperoxidation at its catalytic cysteine residue to generate sulfinic/sulfonic derivatives, a reaction facilitating ferroptosis. Building on this biology, here we outline a method that detects ferroptosis in cells and tissues using 5H7c, a rabbit monoclonal antibody recognizing hyperoxidized but not unmodified PRDX3. The approach offers high specificity, broad sample compatibility (cell lines, animal tissues), and platform flexibility (Western blotting, immunohistochemistry, immunofluorescence).