Articles by Chelsea Samson in JoVE
שלב מעבר לברט: הקרינה על ידי מאוגד עירור מההארה (דלק) Joseph Dragavon1, Carolyn Sinow2, Alexandra D. Holland1, Abdessalem Rekiki1, Ioanna Theodorou3, Chelsea Samson4, Samantha Blazquez1, Kelly L. Rogers5, Régis Tournebize1,6,7, Spencer L. Shorte1 1Plate-Forme d'Imagerie Dynamique, Imagopole, Institut Pasteur, 2Department of Radiation Oncology, Stanford School of Medicine, 3 הרחבת הבסיס ותחולתה של הקרינה על ידי מאוגד עירור מהארה (דלק) על ידי מדידות העקרונות הרלוונטיים והוכחת התאימות שלה עם שפע של fluorophores ותנאים ממוקדי נוגדן.
Other articles by Chelsea Samson on PubMed
In Vivo Excitation of Nanoparticles Using Luminescent Bacteria Proceedings of the National Academy of Sciences of the United States of America. Jun, 2012 | Pubmed ID: 22615349 The lux operon derived from Photorhabdus luminescens incorporated into bacterial genomes, elicits the production of biological chemiluminescence typically centered on 490 nm. The light-producing bacteria are widely used for in vivo bioluminescence imaging. However, in living samples, a common difficulty is the presence of blue-green absorbers such as hemoglobin. Here we report a characterization of fluorescence by unbound excitation from luminescence, a phenomenon that exploits radiating luminescence to excite nearby fluorophores by epifluorescence. We show that photons from bioluminescent bacteria radiate over mesoscopic distances and induce a red-shifted fluorescent emission from appropriate fluorophores in a manner distinct from bioluminescence resonance energy transfer. Our results characterizing fluorescence by unbound excitation from luminescence, both in vitro and in vivo, demonstrate how the resulting blue-to-red wavelength shift is both necessary and sufficient to yield contrast enhancement revealing mesoscopic proximity of luminescent and fluorescent probes in the context of living biological tissues.
In Vitro and in Vivo Demonstrations of Fluorescence by Unbound Excitation from Luminescence (FUEL) Methods in Molecular Biology (Clifton, N.J.). 2014 | Pubmed ID: 24166383 Bioluminescence imaging is a powerful technique that allows for deep-tissue analysis in living, intact organisms. However, in vivo optical imaging is compounded by difficulties due to light scattering and absorption. While light scattering is relatively difficult to overcome and compensate, light absorption by biological tissue is strongly dependent upon wavelength. For example, light absorption by mammalian tissue is highest in the blue-yellow part of the visible energy spectrum. Many natural bioluminescent molecules emit photonic energy in this range, thus in vivo optical detection of these molecules is primarily limited by absorption. This has driven efforts for probe development aimed to enhance photonic emission of red light that is absorbed much less by mammalian tissue using either direct genetic manipulation, and/or resonance energy transfer methods. Here we describe a recently identified alternative approach termed Fluorescence by Unbound Excitation from Luminescence (FUEL), where bioluminescent molecules are able to induce a fluorescent response from fluorescent nanoparticles through an epifluorescence mechanism, thereby significantly increasing both the total number of detectable photons as well as the number of red photons produced.