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

Raman Spectroscopy: Overview

Raman Spectroscopy: Overview

The underlying principle of Raman spectroscopy is based on the interaction between light and matter, specifically molecules' inelastic scattering of photons. When a monochromatic beam of light, typically from a laser source, interacts with a sample, most scattered light has the same frequency as the incident light. This is known as Rayleigh scattering.
However, a small fraction of the scattered light exhibits a frequency shift due to the exchange of energy between the incident photons and the...

Raman Spectroscopy Instrumentation: Overview

Raman Spectroscopy Instrumentation: Overview

A conventional Raman spectrophotometer includes a laser source, a sample holding system, a wavelength selector, and a detector.
The monochromatic laser source, typically using visible or near-infrared radiation, generates a highly focused beam of light. This light interacts with the molecules of the sample, scattering some of the light. Liquid and gaseous samples are usually tested in ordinary glass capillaries, while solids can be analyzed as powders packed in capillaries or as potassium...

Super-resolution Fluorescence Microscopy

Super-resolution Fluorescence Microscopy

Super-resolution fluorescence microscopy (SRFM) provides a better resolution than conventional fluorescence microscopy by reducing the point spread function (PSF). PSF is the light intensity distribution from a point that causes it to appear blurred. Due to PSF, each fluorescing point appears bigger than its actual size, and it is the PSF interference of nearby fluorophores that causes the blurred image. Various approaches to achieving higher resolution through SRFM have recently been developed.

Total Internal Reflection Fluorescence Microscopy

Total Internal Reflection Fluorescence Microscopy

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.

Confocal Fluorescence Microscopy

Confocal Fluorescence Microscopy

Confocal microscopy is an advanced microscopic technique. The prime advantage of the confocal microscope over other microscopy techniques is its ability to block the out-of-focus light from the illuminated samples using pinholes. It is widely used with fluorescence optics to obtain high-resolution, sharp contrast images. Unlike optical microscopes, confocal microscopes use a focused beam of light laser to scan the entire sample surface at different z-planes. These microscopes are, therefore,...

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.

You might also read

Related Articles

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

Sort by

Same author

Speckle-based measurement of the fractional azimuthal index of orbital angular momentum beams for refractive index sensing.

Nature communications·2026

Same author

Superconducting nanowire single-photon detectors for enhanced biomedical imaging.

Journal of biomedical optics·2026

Same author

Molecular Profiling and Tumor Biomarker Analysis of GOG281/LOGS: A Positive Late-Phase Trial of Trametinib for Recurrent/Persistent Low-Grade Serous Ovarian Carcinoma.

Clinical cancer research : an official journal of the American Association for Cancer Research·2025

Same author

CO<sub>2</sub> Isotopologue Quantification Using Direct Frequency Comb Spectroscopy and Machine Learning.

ACS omega·2025

Same author

Engineering gold nanoparticles aggregation in acrylate hydrogel-photopolymers for SERS-based on-site highly sensitive dimethoate detection on olives.

Food chemistry·2025

Same author

TGF-β1-mediated downregulation of L1CAM in pancreatic ductal adenocarcinoma drives upregulation of collagen 17A1 and MMP2, facilitating tumor invasiveness and metastasis.

Cell death & disease·2025

Search research articles

Related Experiment Video

Updated: Jun 17, 2026

Rejection of Fluorescence Background in Resonance and Spontaneous Raman Microspectroscopy

Rejection of Fluorescence Background in Resonance and Spontaneous Raman Microspectroscopy

Published on: May 18, 2011

Online fluorescence suppression in modulated Raman spectroscopy.

Anna Chiara De Luca¹, Michael Mazilu, Andrew Riches

¹SUPA, School of Physics and Astronomy, University of St Andrews, North Haugh, St. Andrews, Fife, KY16 9SS, United Kingdom.

Analytical Chemistry

|December 19, 2009

Summary

This study introduces modulated Raman spectroscopy to remove fluorescence background for cell chemical analysis. The technique enhances signal quality, enabling sensitive, localized chemical characterization of cellular components.

More Related Videos

A Multimodal Wide-Field Fourier-Transform Raman Microscope

A Multimodal Wide-Field Fourier-Transform Raman Microscope

Published on: December 30, 2025

Ultrafast Time-resolved Near-IR Stimulated Raman Measurements of Functional π-conjugate Systems

Ultrafast Time-resolved Near-IR Stimulated Raman Measurements of Functional π-conjugate Systems

Published on: February 10, 2020

Related Experiment Videos

Last Updated: Jun 17, 2026

Rejection of Fluorescence Background in Resonance and Spontaneous Raman Microspectroscopy

Rejection of Fluorescence Background in Resonance and Spontaneous Raman Microspectroscopy

Published on: May 18, 2011

A Multimodal Wide-Field Fourier-Transform Raman Microscope

A Multimodal Wide-Field Fourier-Transform Raman Microscope

Published on: December 30, 2025

Ultrafast Time-resolved Near-IR Stimulated Raman Measurements of Functional π-conjugate Systems

Ultrafast Time-resolved Near-IR Stimulated Raman Measurements of Functional π-conjugate Systems

Published on: February 10, 2020

Area of Science:

Biomedical Optics
Spectroscopy
Cellular Imaging

Background:

Label-free chemical characterization of single cells is crucial for biomedical research.
Standard Raman spectroscopy offers intrinsic biochemical markers but is often limited by fluorescence background.
Effective fluorescence subtraction is needed for accurate Raman analysis of biological samples.

Purpose of the Study:

To present an innovative modulated Raman spectroscopy technique for filtering fluorescence background.
To demonstrate the method's ability to provide online, time-efficient fluorescence suppression.
To evaluate the technique's performance in obtaining localized chemical information from cells.

Main Methods:

Modulated Raman spectroscopy based on periodical laser wavelength modulation.
Multichannel lock-in detection for enhanced Raman signal acquisition.
Analysis of modulated Raman and shifted excitation Raman difference spectroscopy (SERDS) signals using polystyrene beads and Chinese hamster ovary (CHO) cells.

Main Results:

The modulated Raman spectroscopy technique effectively filters Raman spectra from fluorescence background.
Signal-to-noise ratio of modulated Raman spectra was 3 times higher than SERDS at the highest modulation rate.
The method successfully obtained localized chemical information from CHO cell membranes, cytoplasm, and nucleus.

Conclusions:

Modulated Raman spectroscopy provides an effective, online, and less time-consuming method for fluorescence suppression in biological samples.
The technique enables sensitive and specific distinction between different cellular locations using principal component analysis (PCA).
This method avoids misinterpretation of data caused by interfering fluorescence, advancing label-free cellular analysis.