title: Optical detection of singlet oxygen from single cells.
abstract: The lowest excited electronic state of molecular oxygen, singlet molecular oxygen, O(2)(a (1)Delta(g)), is a reactive species involved in many chemical and biological processes. To better understand the roles played by singlet oxygen in biological systems, particularly at the sub-cellular level, optical tools have been developed to create and directly detect this transient state in time- and spatially-resolved experiments from single cells. Data obtained indicate that, contrary to common perception, this reactive species can be quite long-lived in a cell and, as such, can diffuse over appreciable distances including across the cell membrane into the extracellular environment. On one hand, these results demonstrate that the behavior of singlet oxygen in an intact cell can be significantly different from that inferred from model bulk studies. More generally, these results provide a new perspective for mechanistic studies of intra- and inter-cellular signaling and events that ultimately lead to photo-induced cell death.
authors.affiliation: Department of Chemistry, Center for Oxygen Microscopy and Imaging, University of Aarhus, DK-8000 Arhus, Denmark.
authors.forename: John W
authors.initials: JW
authors.lastname: Snyder
authors.forename: Esben
authors.initials: E
authors.lastname: Skovsen
authors.forename: John D C
authors.initials: JD
authors.lastname: Lambert
authors.forename: Lars
authors.initials: L
authors.lastname: Poulsen
authors.forename: Peter R
authors.initials: PR
authors.lastname: Ogilby
mesh_terms: D002478:Cells, Cultured; D005453:Fluorescence; D008853:Microscopy / Q000379:methods; D009474:Neurons / Q000378:metabolism* / Q000648:ultrastructure; D055095:Optics and Photonics; D010777:Photochemistry; D017785:Photons; D017319:Photosensitizing Agents; D011166:Porphyrins; D017382:Reactive Oxygen Species / Q000378:metabolism*; D026082:Singlet Oxygen / Q000378:metabolism*
chemical_list: D017319:Photosensitizing Agents; D011166:Porphyrins; D017382:Reactive Oxygen Species; D026082:Singlet Oxygen; C021096:tetra(4-N-methylpyridyl)porphine