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Quorum Sensing and Essential Oils
Published in K. Hüsnü Can Başer, Gerhard Buchbauer, Handbook of Essential Oils, 2020
Isabel Charlotte Soede, Gerhard Buchbauer
Cinnamomum verum (cort.) EO, containing mainly trans-cinnamaldehyde (72.8%), benzyl alcohol (12.5%), and eugenol (6.6%) (GC-MS results) was tested on the ability to inhibit QS measured by bioluminescence of two E. coli strains as listed below. Concentrations of 0.01%, 0.0075%, and 0.005% significantly inhibited bioluminescence dose-dependently, whereas no antimicrobial effect was observed at these concentrations (Yap et al., 2015). EO: C. verum (cort.) EOSensor strains: E. coli [pSB401] and E. coli [pSB1075] supplemented with C6-HSL/3-oxo-C12-HSLPerformed assay: Bioluminescence assay
Lab-on-a-Chip-Based Devices for Rapid and Accurate Measurement of Nanomaterial Toxicity
Published in Suresh C. Pillai, Yvonne Lang, Toxicity of Nanomaterials, 2019
Mehenur Sarwar, Amirali Nilchian, Chen-zhong Li
Bioluminescence and chemiluminescence represent similar phenomena. Because of a series of chemical reactions, reactive compounds give rise to a molecule which is in an electronically excited state. Ultimately, the excited molecule returns to its ground states (lower energy level) and emits characteristic photons of light. In fact, bioluminescence is a subcategory of chemiluminescence, where the source of emission is a bio-molecule. For example, a class of different bio-compounds called Luciferin are the source of bioluminescence in several living organisms. Light-emitting Luciferin molecules reach their excited state as a result of oxidative-chemical reactions. Typically, an enzyme from a class of oxidative-enzymes called Luciferase couples with the corresponding Luciferin molecule to catalyse the reaction. In summary, chemiluminescence is the emission of light due to chemical reactions while bioluminescence is the emission of light from living organisms (Mirasoli et al. 2014; Roggo and van der Meer 2017).
Optical-CT Imaging
Published in George C. Kagadis, Nancy L. Ford, Dimitrios N. Karnabatidis, George K. Loudos, Handbook of Small Animal Imaging, 2018
Xueli Chen, Dongmei Chen, Fenglin Liu, Wenxiang Cong, Ge Wang, Jimin Liang
When fluorophores, fluorochromes, or fluorescent dyes are excited by an external excitation source, such as a laser, their molecules would absorb light and raise their energy levels to a brief excited state. As they decay from this excited state, they emit fluorescent light (Biosciences 2002). Compared with bioluminescence, fluorescence requires an external light source to stimulate the emission of light with larger signals from probe. However, these signals are usually accompanied by autofluorescence that brings down the quality of image (Zavattini et al. 2006). In particular, FMT is an imaging method aimed at resolving fluorescence distribution in tissues in vivo. The method scans focused light at multiple positions on an animal surface at one or more wavelengths and collects excited fluorescence photons propagating through the tissue for each focal spot.
Advances in luminescence-based technologies for drug discovery
Published in Expert Opinion on Drug Discovery, 2023
Bolormaa Baljinnyam, Michael Ronzetti, Anton Simeonov
Chemiluminescence is a phenomenon of light emission derived from a chemical reaction when chemically excited electrons return to the ground state. Bioluminescence, a type of chemiluminescence, refers to the photon-emitting processes occurring in living organisms often used to ward off predators, attract prey, or as a means of communication. The machinery responsible for bioluminescence is evolutionarily conserved among marine creatures such as bacteria, planktons, algae, crustaceans, squids, and fish but is also found in terrestrial organisms like bacteria, fungi, worms, and insects [1,2]. These bioluminescent reactions rely on enzymes, termed luciferases, that catalyze the oxidation of a family of substrates called luciferins, resulting in the emission of a photon. The luciferase family of proteins, as well as their luciferin substrates, are as structurally diverse as the organisms from which they are derived, each with their own fingerprint wavelength and quantum yield.
A novel multimeric IL15/IL15Rα-Fc complex to enhance cancer immunotherapy
Published in OncoImmunology, 2021
Hong Xu, Ilia N. Buhtoiarov, Hongfen Guo, Nai-Kong V. Cheung
All animal procedures were performed in compliance with Institutional Animal Care and Use Committee (IACUC) guidelines. For in vivo therapy studies, BALB-Rag2-/-IL2R-γc-KO (DKO) mice (from Taconic as CIEA BRG mice)10 or C57BL/6 mice (The Jackson Laboratory) were used. Effector PBMCs were prepared as described above. Prior to every experimental procedure, PBMCs were analyzed by flow cytometry for relative percentage of CD3, CD4, CD8 and CD56 cells to ensure consistency. Subcutaneous (sc) xenografts were created by implanting the tumor cells suspended in Matrigel (Corning Corp) in the flank of mice. Treatments were started when sc tumor size was reached 50–100 mm3 in general, or once successful iv tumor engraftment was confirmed by bioluminescence. Treatment schedules were marked on the figures, and doses of IL15 complexes, antibodies and effector cells were detailed in the Results section. Tumor size was measured using 1) hand-held TM900 scanner (Pieira, Brussels, BE), 2) Calipers, or 3) Bioluminescence. Bioluminescence imaging was conducted using the Xenogen In Vivo Imaging System (IVIS) 200 (Caliper LifeSciences). Briefly, mice were injected intravenously (iv) with 0.1 mL solution of D-luciferin (Gold Biotechnology; 30 mg/mL stock in PBS). Images were collected 1 to 2 minutes after injection using the following parameters: a 10- to 60-second exposure time, medium binning, and an 8 f/stop. Bioluminescence image analysis was performed using Living Image 2.6 (Caliper LifeSciences).
Persistence and dynamics of fluorescent Lactobacillus plantarum in the healthy versus inflamed gut
Published in Gut Microbes, 2021
Sophie Salomé-Desnoulez, Sabine Poiret, Benoit Foligné, Ghaffar Muharram, Véronique Peucelle, Frank Lafont, Catherine Daniel
The three strains’ respective bioluminescence and fluorescence signals were quantified daily by direct imaging in six anesthetized mice per group (Fig. S2). Relative to LpCBRluc/mCherry, the bioluminescence signal obtained with Lp-CBRluc and the fluorescence signal obtained with Lp-mCherry were consistently stronger throughout the experiments. Bioluminescence detection was more sensitive than fluorescence detection because the latter’s background signal was much stronger. In fact, the fluorescence signal was at the background level on day 6, whereas bioluminescence could still be detected on day 6 and only dropped to the background level on day 7 (as described previously12). However, given that our primary objective was to track L. plantarum in the mouse gut by combining in vivo whole-body imaging with ex vivo microscopy, Lp-mCherry was chosen for all further experiments because its fluorescence signals in live mice were much stronger than those of Lp-CBRluc/mCherry.