
Advanced Healthcare Materials, Journal Year: 2025, Volume and Issue: unknown
Published: April 29, 2025
Abstract Negative‐ and positive‐staining transmission electron microscopy (ns/psTEM) is a cornerstone of research diagnostics, enabling nanometer‐resolution analysis organic specimens from nanoparticles to cells without requiring costly cryo‐equipment. For nearly 70 years, uranyl salts like acetate (UA) have been the gold‐standard ns/psTEM‐stains. However, mounting safety concerns due their high toxicity radioactivity led stricter regulations expensive licensing requirements. Consequently, there an urgent global demand for safer, more sustainable stains that deliver uranyl‐comparable, high‐quality ns/psTEM. Here, commercially available stain‐alternatives UranyLess, UAR, UA‐Zero, PTA, STAIN 77, Nano‐W, NanoVan, lead citrate are systematically assessed against UA. The evaluated regarding contrast, resolution, stain‐distribution, ease‐of‐use in ns/psTEM across diverse sample set, including polymethylmethacrylate‐nanoplastics, phosphatidylcholine‐liposomes, Influenza‐A viruses, globular ferritin, fibrillar pyruvate kinase amyloids, human lung‐carcinoma cell‐sections. It shown this variety samples, ready‐to‐use uranyl‐alternative with comparable or even superior ns/psTEM‐performance UA using efficient staining‐protocol. Furthermore, GUIDE4U tool developed fast identification appropriate uranyl‐replacements each interest, saving ns/psTEM‐users time costs while ensuring excellent staining results ultrastructural analysis, thereby further catalyzing use safer stains.
Language: Английский