Related Experiment Video
Updated: Jun 22, 2026
08:56
Visualizing the Interaction Between the Qdot-labeled Protein and Site-specifically Modified λ DNA at the Single Molecule Level
Published on: July 17, 2018
In situ visualization of gene expression using polymer-coated quantum-dot-DNA conjugates
Youngseon Choi1, Hwa Pyung Kim, Suk Min Hong
1Nano/Bio Chemistry Group, Institut Pasteur Korea, Seongnam, South Korea.
Small (Weinheim an Der Bergstrasse, Germany)
|June 12, 2009
Summary
Quantum dots (QDs) enable precise imaging of mRNA in cells. This new method allows accurate quantification and localization of gene expression, advancing cell signaling research.
Area of Science:
- Molecular Biology
- Cell Biology
- Biotechnology
Background:
- Subcellular mRNA localization is crucial for protein production.
- Understanding gene expression dynamics requires precise mRNA detection methods.
Purpose of the Study:
- To develop and validate quantum dot (QD)-based probes for accurate mRNA imaging and quantification in situ.
- To assess the sensitivity and multiplexing capabilities of QD-DNA conjugates for gene expression analysis.
Main Methods:
- Amine-modified oligonucleotide probes were conjugated to carboxyl-terminated QDs using EDC chemistry.
- Fluorescence in situ hybridization (FISH) with QD-DNA conjugates was performed on Drosophila cells.
- Quantitative analysis of FISH signals was correlated with quantitative real-time PCR.
Main Results:
- QD-DNA probes demonstrated sequence-specific hybridization and high sensitivity for detecting low-expressing genes.
- FISH signal intensity correlated with LPS concentration, aligning with qPCR data.
- Multiplex FISH successfully visualized the simultaneous distribution of two independent genes using different colored QD-DNA probes.
Conclusions:
- Highly fluorescent and stable QD-DNA probes offer a powerful tool for in situ gene expression localization and quantification.
- This technique enhances the understanding of cellular processes and gene regulation.
Related Concept Videos
03:31Labeling DNA Probes
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...
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...
02:34DNA Microarrays
Microarrays are high-throughput and relatively inexpensive assays that can be automated to analyze large quantities of data at a time. They are used in genome-wide studies to compare gene or protein expression under two varied conditions, such as healthy and diseased states. Microarrays consist of glass or silica slides on which probe molecules are covalently attached through surface functionalization. Most commonly, the slides are prepared through the chemisorption of silanes to silica...
02:07FISH - Fluorescent In-situ Hybridization
Fluorescence in situ hybridization, or FISH, was developed in the early 1980s and has quickly become one of the most widely used techniques in cytogenetics. Labeled probes are used to bind complementary DNA or RNA sequences on a chromosome or in a region within a cell. Earlier, the probes could only be obtained by cloning or reverse transcription of a DNA template. Currently, the probe oligonucleotides can be synthesized synthetically. Additionally, with the advancement of optical techniques,...
02:31In-situ Hybridization
In situ hybridization (ISH) is a technique used to detect and localize specific DNA or RNA molecules in cells, tissue, or tissue sections using a labeled probe. The technique was first used in 1969 for the investigation of nucleic acids. It is currently an essential tool in scientific research and clinical settings, especially for diagnostic purposes.
Types of probes and labels
A probe is a complementary strand of DNA or RNA that binds to corresponding nucleotide sequences in a cell. Many...
Types of probes and labels
A probe is a complementary strand of DNA or RNA that binds to corresponding nucleotide sequences in a cell. Many...
02:11Reporter Genes
Reporter genes are a type of protein-coding gene that are often tagged to a gene of interest. Once inside a target cell, reporter genes usually produce visually identifiable characteristics like fluorescence and luminescence when expressed along with the gene of interest. Thus, reporter genes “report” the presence or absence of genes of interest in an organism, determine the gene expression pattern, or track the physical location of a DNA segment or protein in the cell.
Commonly used reporter...
Commonly used reporter...
02:57Real Time RT-PCR
Real-time reverse transcription-polymerase chain reaction, or Real-time RT-PCR, is an analytical tool used to determine the expression level of target genes. The method involves converting mRNA to complementary DNA with the help of an enzyme known as reverse transcriptase, followed by the PCR amplification of the cDNA. These two processes can be performed simultaneously in a single tube or separately as a two-step reaction.
The real-time quantification of the number of amplified products is...
The real-time quantification of the number of amplified products is...