Total Fluorescence Yield
Total Fluorescence Yield - Related Videos
01:31
ATP Yield
0 Views •
2019
Cellular respiration produces 30 - 32 ATP per glucose molecule. Although most of the ATP results from oxidative phosphorylation and the electron transport chain (ETC), 4 ATP are gained beforehand (2 from glycolysis and 2 from the citric acid cycle). The ETC is embedded in the inner mitochondrial membrane and is comprised of four main protein complexes and an ATP synthase. NADH and FADH2 pass electrons to these complexes, which pump protons into the intermembrane space. This distribution of...
01:05
Total Internal Reflection Fluorescence Microscopy
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2023
Total internal reflection fluorescence microscopy or TIRF is an advanced microscopic technique used to visualize fluorophores in samples close to a solid surface with a higher refractive index, such as a glass coverslip. TIRF only allows fluorophores in proximity to the solid surface to be excited. When light from a medium with a lower refractive index (such as air) hits the glass coverslip at a critical angle, the light undergoes total internal reflection stead of passing through the glass.
02:51
Cell Imaging Using Total Internal Reflection Fluorescence Microscopy
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2025
Source: Daniele, F., et. al TIRFM and pH-sensitive GFP-probes to Evaluate Neurotransmitter Vesicle Dynamics in SH-SY5Y Neuroblastoma Cells: Cell Imaging and Data Analysis. J. Vis. Exp. (2015).This video demonstrates the imaging of human neuroblastoma cells using a total internal reflection fluorescence (TIRF) microscope to visualize fluorophore-tagged synaptic vesicles. The cells are first focused in epifluorescence mode. Adjustments are then made to achieve total internal reflection,...
03:54
Total Internal Reflection Fluorescence Microscopy for Visualization of Exocytic Events
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Source: Winkle, C. C., et al. Utilizing Combined Methodologies to Define the Role of Plasma Membrane Delivery During Axon Branching and Neuronal Morphogenesis. J. Vis. Exp. (2016)This video demonstrates total internal reflection fluorescence (TIRF) microscopy for visualizing exocytic events in cortical neurons. A pH-sensitive green fluorescent protein (GFP) marker fluoresces upon vesicle fusion, with selective TIRF excitation capturing membrane-proximal exocytosis in time-lapse imaging.
02:22
Reaction Yield
0 Views •
2020
The theoretical yield of a reaction is the amount of product estimated to form based on the stoichiometry of the balanced chemical equation. The theoretical yield assumes the complete conversion of the limiting reactant into the desired product. The amount of product that is obtained by performing the reaction is called the actual yield, and it may be less than or (very rarely) equal to the theoretical yield. Percent Yield In the case of chemical reactions, the actual yield of the product is...
FAQs
The measured photons originate after an incident X-ray causes a core electron to be ejected. The vacancy then is filled by an electron from a higher energy level, and the released energy appears as characteristic fluorescence. A detector collects these emitted photons, linking the absorption event to the recorded spectrum.
Combining the relevant fluorescence lines gives a signal that represents the total emitted intensity rather than a single selected line. This matters because the recorded response includes all relevant fluorescence contributions produced following absorption. The resulting spectrum can therefore serve as an element-selective measure of the sample's absorption.
The measured absorption spectrum can be examined in XANES and EXAFS studies. Within chemistry applications, these measurements are used to investigate oxidation state and coordination environment, while the element-selective response also supports elemental composition analysis. This connects the detected fluorescence signal with chemical-state and composition questions.
Total Fluorescence Yield is especially relevant for studies of bulk or dilute materials. Its fluorescence signal supplies an element-selective absorption measure while combining the relevant emitted lines. That capability supports chemical investigations in samples where researchers need information about oxidation state, coordination environment, or elemental composition.
The sequence begins by directing incident X-rays onto the sample. Absorption ejects a core electron, and a higher-level electron fills the resulting vacancy, producing characteristic fluorescence. A detector records the emitted photons, and their combined intensity is used to generate the absorption spectrum for subsequent chemical analysis.
The detector records photons emitted by the sample after X-ray absorption and the subsequent electronic transition. Because the relevant fluorescence lines contribute to the measured signal, the recorded intensity reflects the combined emission. Processing this detector response produces an absorption spectrum that can be evaluated for element-selective chemical information.
Chemists can use this approach when a study requires element-selective absorption information from bulk or dilute materials. The resulting spectrum supports XANES and EXAFS investigations focused on oxidation state, coordination environment, and elemental composition. It is therefore applicable to samples where fluorescence detection provides the basis for analyzing these chemical characteristics.