Fluorescent Probe Labeling
Fluorescent Probe Labeling - Related Videos
12:16
Robust 3D DNA FISH Using Directly Labeled Probes
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Cited by 49 •
2013
We describe a robust and versatile protocol for analyzing nuclear architecture by 3D DNA FISH using directly labeled fluorescent probes.
03:31
Labeling DNA Probes
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2021
DNA probes are fragments of DNA labeled with a reporter tag to enable their detection or purification. The resulting labeled DNA probes can then hybridize to target nucleic acid sequences through complementary base-pairing, and may be used to recover or identify these regions. Radioisotopes, fluorophores, or small molecule binding partners like biotin or digoxigenin, are the most widely used reporter tags for labeling DNA probes. These labels can be attached to the probe DNA molecule via...
11:12
Fluorescent Labeling of Drosophila Heart Structures
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Cited by 63 •
2009
Here we describe a basic protocol for fluorescent labeling of different elements of heart tubes from larva and adult Drosophila melanogaster. These specimens are well-suited for imaging via fluorescent or confocal microscopy. This technique permits detailed structural analysis of the features of the hearts from a powerful model organism.
04:02
An Assay to Measure the Accumulation of a Fluorescent Antibiotic Probe in Bacterial Cells
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2025
This video demonstrates an assay to measure the accumulation of a fluorescent antibiotic probe in bacterial cells. Exposure to an efflux pump inhibitor disrupts the transmembrane proton gradient in bacterial cells, upon which a fluorophore-conjugated antibiotic is added. Inhibition of efflux pumps due to the disrupted proton gradient causes accumulation of the antibiotic inside the bacteria. Bacterial cells are lysed, and the fluorescence intensity is measured to confirm antibiotic accumulation.
07:14
Assessing Phagocytic Clearance of Cell Death in Experimental Stroke by Ligatable Fluorescent Probes
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Cited by 4 •
2014
We present a new fluorescence technique for selective in situ labeling of active phagocytic cells, which clear off cell corpses in stroke. The approach is important for assessing brain reaction to ischemia because only a small proportion of phagocytes present in ischemic brain participate in clearance of cell death.
FAQs
When the attached fluorophore absorbs light at a suitable excitation wavelength, it emits light at a longer wavelength. This difference allows detectors to separate the signal from some background and associate the measured fluorescence with the labeled biological target. The resulting signal can reveal target location, indicate relative abundance, or track changes in behavior.
A probe can associate with its target through binding or become attached through covalent coupling. Binding-based labeling uses the recognition between a probe and a protein, nucleic acid, cell component, or analyte, whereas covalent coupling creates a chemical attachment. This distinction determines how the label is connected to the target during the measurement.
Detection depends on choosing a fluorophore with an appropriate excitation and emission range and using instrumentation that distinguishes emitted light from background. The target's abundance, location, and behavior also affect the observed signal. These factors influence whether labeling supports visualization, comparison of molecular amounts, or monitoring of biological changes.
A typical workflow selects a probe for the biological target, attaches or binds the fluorophore through the appropriate labeling strategy, and then exposes the labeled sample to suitable excitation light. A detector records the emitted signal and relates it to target distribution, abundance, or behavior. The exact workflow depends on the target and assay format.
Labeled antibodies can identify proteins, while labeled oligonucleotides can target nucleic acids. Small-molecule probes provide another route for examining biological analytes or cell components. These probe classes extend fluorescent measurements across different molecular targets, allowing researchers to select a labeling approach that matches the biological question and the sample being studied.
Fluorescence microscopy can show where labeled targets are distributed, flow cytometry can measure labeled features across cells, and biochemical assays can quantify interactions or analyte-related signals. Choosing among these platforms changes the type of result obtained, from spatial visualization to cell-based measurement or biochemical quantification.
The method makes molecular targets accessible for direct measurement in biological studies. Researchers can examine cellular processes, investigate disease mechanisms, and support diagnostic development by observing molecular distribution, measuring relative abundance, or monitoring interactions. Its value comes from linking a detectable light signal to otherwise difficult-to-see biological components.