Search research articles

ABOUT JoVE

Overview Leadership Blog JoVE Help Center

AUTHORS

Publishing Process Editorial Board Scope & Policies Peer Review FAQ Submit

LIBRARIANS

Testimonials Subscriptions Access Resources Library Advisory Board FAQ

RESEARCH

JoVE Journal Methods Collections JoVE Encyclopedia of Experiments Archive

EDUCATION

JoVE Core JoVE Business JoVE Science Education JoVE Lab Manual Faculty Resource Center Faculty Site

Terms & Conditions of Use

Related Concept Videos

Fluorescence and Phosphorescence: Instrumentation

Fluorescence and Phosphorescence: Instrumentation

Fluorometers and spectrofluorometers are two types of instruments used for measuring molecular fluorescence. These instruments differ in how they select excitation and emission wavelengths and the type of light sources they utilize. Fluorometers use absorption interference filters to choose excitation and emission wavelengths. The excitation source in a fluorometer is typically a low-pressure mercury vapor lamp that emits intense lines distributed throughout the ultraviolet and visible regions.

Photoluminescence: Applications

Photoluminescence: Applications

Photoluminescence offers a wide range of applications due to its inherent sensitivity and selectivity. This technique allows for both direct and indirect analyses of the analyte. Direct quantitative analysis is possible when the analyte exhibits a favorable quantum yield for fluorescence or phosphorescence. However, an indirect analysis may be feasible if the analyte is not fluorescent or phosphorescent, or if the quantum yield is unfavorable. Indirect methods include reacting the analyte with...

Variables Affecting Phosphorescence and Fluorescence

Variables Affecting Phosphorescence and Fluorescence

Fluorescence and phosphorescence are essential phenomena in fields like analytical chemistry, biological imaging, and materials science, where they detect molecular properties and visualize cellular structures. Understanding the variables that influence these luminescent behaviors is crucial for maximizing accuracy and efficiency in their applications. These variables can broadly be grouped into chemical structure, solvent properties, and external conditions, each playing a distinct role in...

Protein Dynamics in Living Cells

Protein Dynamics in Living Cells

Different fluorescence-based techniques are used to study the protein dynamics in living cells. These techniques include FRAP, FRET, and PET.
Fluorescent recovery after photobleaching (FRAP) is a fluorescent-protein-based detection technique used to quantify protein movement rates within the cell. This method exposes a small portion of the cell to an intense laser beam. The laser beam causes permanent photobleaching of the fluorophore-tagged proteins in the exposed region. As the bleached...

Phasors

Phasors

Phasors are a powerful mathematical tool used to analyze alternating current (AC) circuits. They provide a complex number representation of sinusoids, with the magnitude of the phasor equating to the amplitude of the sinusoid and the angle of the phasor representing the phase measured from the positive x-axis.
One of the significant benefits of using phasors is that they simplify the analysis of AC circuits by eliminating the time dependence of the current and voltage. This transformation...

Photoluminescence: Fluorescence and Phosphorescence

Photoluminescence: Fluorescence and Phosphorescence

Photoluminescence is a process where a molecule absorbs light energy and re-emits it in the form of light. This phenomenon occurs when a substance absorbs photons, promoting its electrons to higher energy level excited states, followed by a relaxation process in which the electrons return to their original ground state energy levels and emit light. Photoluminescence is widely observed in various materials, including semiconductors, and organic and inorganic compounds.
A pair of electrons in a...

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by

Same author

Quantitative and unbiased lung alveolar septum assessment in an LPS experimental mouse model using 2D-spatial correlation image analysis from hematoxylin and eosin slides.

BioTechniques·2026

Same author

Spectral Phasor Analysis for Hyperspectral Imaging to Elucidate Acridine Orange Photophysics in Cells.

Microscopy research and technique·2026

Same author

Redefining colocalization analysis with a novel phasor mixing coefficient.

Journal of cell science·2025

Same author

Biophysical reviews (ISSUE 2 2025): LAFeBS, alive, kicking, and growing: the story continues...

Biophysical reviews·2025

Same author

Challenges of microscopy technology dissemination to resource-constrained communities.

Nature methods·2025

Same author

LAFeBS, alive, kicking, and growing: the story continues….

Biophysical reviews·2024

Search research articles

Related Experiment Video

Updated: May 17, 2025

FLIM-FRET Measurements of Protein-Protein Interactions in Live Bacteria.

FLIM-FRET Measurements of Protein-Protein Interactions in Live Bacteria.

Published on: August 25, 2020

Fluorescence phasor analysis: basic principles and biophysical applications.

Alvaro A Recoulat Angelini^1,2, Leonel Malacrida^3,4, F Luis González Flecha^1,2

¹Laboratorio de Biofísica Molecular, Instituto de Química y Fisicoquímica Biológicas, Universidad de Buenos Aires - CONICET, Buenos Aires, Argentina.

Biophysical Reviews

|May 16, 2025

Summary

The fluorescence phasor concept, originating from circuit analysis, offers a powerful, model-free method for quantitative biophysics. This technique simplifies complex fluorescence data for diverse molecular studies.

Keywords:

Fluorescence spectroscopy Fourier transform Model-free methods Phasor analysis

More Related Videos

Author Spotlight: Standardizing Spheroid Formation Methods for Metabolic and Oxygenation Analysis Using Fluorescence Lifetime Imaging Microscopy

Author Spotlight: Standardizing Spheroid Formation Methods for Metabolic and Oxygenation Analysis Using Fluorescence Lifetime Imaging Microscopy

Published on: August 9, 2024

Time-Resolved Fluorescence Anisotropy from Single Molecules for Characterizing Local Flexibility in Biomolecules

Time-Resolved Fluorescence Anisotropy from Single Molecules for Characterizing Local Flexibility in Biomolecules

Published on: April 25, 2025

Related Experiment Videos

Last Updated: May 17, 2025

FLIM-FRET Measurements of Protein-Protein Interactions in Live Bacteria.

FLIM-FRET Measurements of Protein-Protein Interactions in Live Bacteria.

Published on: August 25, 2020

Author Spotlight: Standardizing Spheroid Formation Methods for Metabolic and Oxygenation Analysis Using Fluorescence Lifetime Imaging Microscopy

Author Spotlight: Standardizing Spheroid Formation Methods for Metabolic and Oxygenation Analysis Using Fluorescence Lifetime Imaging Microscopy

Published on: August 9, 2024

Time-Resolved Fluorescence Anisotropy from Single Molecules for Characterizing Local Flexibility in Biomolecules

Time-Resolved Fluorescence Anisotropy from Single Molecules for Characterizing Local Flexibility in Biomolecules

Published on: April 25, 2025

Area of Science:

Biophysics
Spectroscopy
Molecular Biology

Background:

Fluorescence spectroscopy is a highly sensitive and versatile technique widely used in biological sciences and biophysics.
The concept of phasors, initially used for alternating current circuits, was adapted for fluorescence spectroscopy by Gregorio Weber.

Purpose of the Study:

To provide a historical overview of the fluorescence phasor concept and its integration into fluorescence spectroscopy.
To explain the fundamental algebraic properties of fluorescence phasors for model-free data analysis.
To illustrate the application of fluorescence phasors in studying various molecular biophysics phenomena.

Main Methods:

Analysis of frequency-domain fluorescence measurements to derive phasor magnitudes (G and S).
Relating phasor magnitudes to the real and imaginary parts of the Fourier transform of time-domain fluorescence intensity.
Reviewing and discussing the mathematical framework and applications of fluorescence phasor analysis.

Main Results:

Fluorescence phasors provide an intuitive, model-free approach to analyze complex fluorescence data.
The G and S phasor values offer a unique representation of fluorescence decay characteristics.
This method is applicable to diverse molecular systems, including proteins, lipids, and nucleic acids.

Conclusions:

The fluorescence phasor approach is a powerful tool for quantitative analysis in molecular biophysics.
Its ability to simplify complex data makes it invaluable for studying phenomena like protein folding and interactions.
Phasor analysis enhances the study of molecular dynamics and structural organization in biological systems.