title: Ultra-weak photon emission from biological samples: definition, mechanisms, properties, detection and applications.
abstract: This review attempts to summarize molecular mechanisms, spectral and intensity properties, detection techniques and applications of ultra-weak photon emission. Ultra-weak photon emission is the chemiluminescence from biological systems where electronically excited species are formed during oxidative metabolic or oxidative stress processes. It is generally accepted that photons are emitted (1) at near UVA, visible, and near IR spectral ranges from 350 to 1300nm and (2) at the intensity of photon emission in the range of several units to several hundreds (oxidative metabolic process) and several hundreds to several thousands (oxidative stress process) photons s(-1)cm(-2). Current development in detection using low-noise photomultiplier tubes and imaging using highly sensitive charge coupled device cameras allows temporal and spatial visualization of oxidative metabolic or oxidative stress processes, respectively. As the phenomenon of ultra-weak photon emission reflects oxidative metabolic or oxidative stress processes, it can be widely used as a non-invasive tool for monitoring of the physiological state of biological systems.
authors.affiliation: Institute of Photonics and Electronics, Academy of Sciences of the Czech Republic, Chaberská 57, 182 00 Prague, Czech Republic.
authors.forename: Michal
authors.initials: M
authors.lastname: Cifra
authors.affiliation: Department of Biophysics, Centre of the Region Haná for Biotechnological and Agricultural Research, Faculty of Science, Palacký University, Šlechtitelů 11, 783 71 Olomouc, Czech Republic. Electronic address: pavel.pospisil@upol.cz.
authors.forename: Pavel
authors.initials: P
authors.lastname: Pospíšil
mesh_terms: D000818:Animals; D006801:Humans; D018462:Photobiology / Q000379:methods*; D017785:Photons; D013057:Spectrum Analysis; D009626:Terminology as Topic
keywords: Charge coupled device; Chemiluminescence; Non-invasive diagnostics; Oxidative stress; Photomultiplier; Singlet oxygen; Triplet excited carbonyl