Fluorescence Measurement
Fluorescence Measurement - Related Videos
14:39
Measuring Phagosome pH by Ratiometric Fluorescence Microscopy
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Cited by 26 •
2015
Phagosomal pH influences phagosome maturation, oxidant production, phagosomal killing as well as antigen presentation. Here we describe a ratiometric method for measuring time-course and endpoint pH changes in individual phagosomes in living phagocytes using fluorescence microscopy.
07:03
In Situ Measurement of Vacuum Window Birefringence using 25Mg+ Fluorescence
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2020
Presented here is a method to measure the birefringence of vacuum windows by maximizing the fluorescence counts emitted by Doppler cooled 25Mg+ ions in an ion trap. The birefringence of vacuum windows will change the polarization states of the laser, which can be compensated by changing the azimuthal angles of external wave plates.
10:09
Thermodynamics of Membrane Protein Folding Measured by Fluorescence Spectroscopy
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Cited by 2 •
2011
This video article details the experimental procedure for obtaining the Gibbs free energy of membrane protein folding by tryptophan fluorescence.
08:17
Fluorescent Nanoparticles for the Measurement of Ion Concentration in Biological Systems
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Cited by 24 •
2011
Fluorescent nanoparticles produced in our lab are used for imaging ion concentrations and ion fluxes in biological systems such as cells during signaling and interstitial fluid during physiological homeostasis.
07:00
Measuring Diffusion Coefficients via Two-photon Fluorescence Recovery After Photobleaching
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Cited by 4 •
2010
In this article we will describe the procedure for measuring diffusion coefficients using multi-photon fluorescence recovery after photobleaching. We will begin by aligning the laser along the optical path to the sample and determining the proper experimental parameters, then continue generating and finally fitting fluorescence recovery curves.
FAQs
The fluorophore emits light at a longer wavelength because it releases only part of the absorbed excitation energy. This separation between incoming and emitted light allows detectors to distinguish the fluorescence signal from the excitation light. Measuring the resulting emission intensity or spectrum helps characterize a biological signal under controlled experimental conditions.
Changes in signal can reflect differences in molecular abundance, molecular interactions, ion concentrations, or cellular physiological responses. The meaning depends on the biological assay or reporter being measured. Consequently, fluorescence measurement can connect an optical change with a molecular or cellular event, supporting quantitative analysis rather than only visual observation.
Intensity measurements quantify how much emitted light a sample produces, whereas spectral measurements examine the properties of that emission across wavelengths. Intensity can support estimates of signal changes, while spectral information can help describe the emitted fluorescence more fully. Both approaches provide complementary data for analyzing molecules, cells, and biological processes.
Excitation and emission must be measured under controlled conditions so that signal differences can be interpreted consistently. Researchers control the illumination used to excite the fluorophore and the detection of emitted light, then compare the resulting intensity or spectral properties. This control is essential when assessing changes in abundance, interactions, ion concentrations, or physiology.
A typical application selects a fluorescent molecule, reporter, or labeled biological target, exposes it to suitable excitation light, and detects the emitted signal. Researchers then quantify emission intensity or examine spectral properties and relate the result to the biological question. The approach can be implemented in microscopy, protein assays, nucleic-acid assays, or cellular studies.
This approach is useful when researchers need information about the location, abundance, or activity of molecules and cells. It supports microscopy, protein and nucleic-acid assays, cellular reporter studies, and quantitative analysis of biological processes. In disease research and diagnostics, fluorescence changes can also help examine molecular interactions or physiological responses.