Probe Labeling
Probe Labeling - Related Videos
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...
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.
11:15
In Situ Detection of Bacteria within Paraffin-embedded Tissues Using a Digoxin-labeled DNA Probe Targeting 16S rRNA
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Cited by 16 •
2015
Here a method to localize bacteria within paraffin-embedded tissues using DIG-labeled 16S rRNA-targeting DNA probes has been described. This protocol can be applied to study the role of bacteria in various diseases such as periodontitis, cancers, and inflammatory immune diseases.
08:28
Metabolic Labeling
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2023
Metabolic labeling is used to probe the biochemical transformations and modifications that occur in a cell. This is accomplished by using chemical analogs that mimic the structure of natural biomolecules. Cells utilize analogs in their endogenous biochemical processes, producing compounds that are labeled. The label allows for the incorporation of detection and affinity tags, which can then be used to elucidate metabolic pathways using other biochemical analytical techniques, such as SDS-PAGE...
09:19
Simultaneous Label-Free Autofluorescence Multi-Harmonic Microscopy
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Cited by 3 •
2025
This protocol presents a step-by-step guide for the Simultaneous Label-free Autofluorescence Multi-harmonic (SLAM) microscopic technique, including details on how to generate the laser light source, prepare a tissue sample, conduct imaging, and analyze the data. SLAM advances nonlinear microscopy by measuring four complementary label-free contrasts to investigate the tissue microenvironment.
FAQs
Markers can be added while a DNA, RNA, or oligonucleotide probe is being synthesized, or they can be introduced afterward through an enzymatic reaction. These approaches place labeled nucleotides or reporter molecules within the probe. The resulting product retains the sequence needed for target recognition while gaining a detectable feature for downstream analysis.
The label determines how the hybridization event becomes measurable. Radioactive markers produce a radiometric signal, fluorescent markers support direct fluorescence-based visualization, and enzyme-linked reporters generate a detectable reaction product. Selecting among these formats connects the molecular recognition step to the readout required for blotting, imaging, or other analytical assays.
A labeled probe provides a signal at the position where it hybridizes with a complementary sequence. This signal makes the target easier to locate or measure than an unlabeled interaction would be. Consequently, labeling supports sensitive analysis of molecular targets in samples used for gene detection, expression studies, and localization experiments.
The same labeling principle supports different biological questions in each format. Southern blotting is used to analyze gene presence, whereas Northern blotting addresses gene expression. Fluorescence in situ hybridization, or FISH, reveals chromosomal location, while microarrays allow labeled probes to participate in broader molecular profiling. The assay determines how the signal is interpreted.
A typical workflow begins by preparing a DNA, RNA, or oligonucleotide probe and attaching a radioactive, fluorescent, or enzyme-generating marker during synthesis or through an enzymatic reaction. The labeled probe is then allowed to hybridize with its complementary target, after which the resulting signal is detected or measured to determine the target's presence or location.
This approach is useful when researchers need more than the probe sequence itself and require a measurable or visible readout. It can support detection of gene presence, assessment of gene expression, or visualization of chromosomal location. The method is therefore relevant to Southern and Northern blotting, FISH, microarrays, and related molecular assays.