Ultraviolet germicidal irradiation and its effects on elemental distributions in mouse embryonic fibroblast cells in x-ray fluorescence microanalysis

• Published in: PloS one Vol. 10; no. 2; p. e0117437
• Main Authors: Jin, Qiaoling, Vogt, Stefan, Lai, Barry, Chen, Si, Finney, Lydia, Gleber, Sophie-Charlotte, Ward, Jesse, Deng, Junjing, Mak, Rachel, Moonier, Nena, Jacobsen, Chris
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 23.02.2015; Public Library of Science (PLoS)
• Subjects: 60 APPLIED LIFE SCIENCES; Animals; Astronomy; BASIC BIOLOGICAL SCIENCES; Biological materials; Contamination; Cryopreservation; Deactivation; Decontamination; dehydration (medicine); Electron Probe Microanalysis - methods; Embryo fibroblasts; Embryonic Stem Cells - chemistry; Embryonic Stem Cells - radiation effects; fibroblasts; Fibroblasts - chemistry; Fibroblasts - radiation effects; Fluorescence; fluorescence imaging; Fluorescence microscopy; Health risks; INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY; Irradiation; Laboratories; Liquid nitrogen; Materials handling; Mice; Microorganisms; Microscopes; Microscopy; Microscopy, Fluorescence; Nitrogen; Pathogens; Physics; RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT; Science; Stem cells; U.V. radiation; Ultraviolet; Ultraviolet radiation; Ultraviolet Rays - adverse effects; X ray fluorescence; X-ray microscopy; X-ray radiography; United States > US; Illinois
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0117437

Rapidly-frozen hydrated (cryopreserved) specimens combined with cryo-scanning x-ray fluorescence microscopy provide an ideal approach for investigating elemental distributions in biological cells and tissues. However, because cryopreservation does not deactivate potentially infectious agents associated with Risk Group 2 biological materials, one must be concerned with contamination of expensive and complicated cryogenic x-ray microscopes when working with such materials. We employed ultraviolet germicidal irradiation to decontaminate previously cryopreserved cells under liquid nitrogen, and then investigated its effects on elemental distributions under both frozen hydrated and freeze dried states with x-ray fluorescence microscopy. We show that the contents and distributions of most biologically important elements remain nearly unchanged when compared with non-ultraviolet-irradiated counterparts, even after multiple cycles of ultraviolet germicidal irradiation and cryogenic x-ray imaging. This provides a potential pathway for rendering Risk Group 2 biological materials safe for handling in multiuser cryogenic x-ray microscopes without affecting the fidelity of the results.