Quantum dot-mediated biosensing assays for specific nucleic acid detection.
AuthorsYeh HC, Ho YP, Wang TH,
JournalNanomedicine
PubMed ID17292066
'Two new classes of quantum dot (QD)-mediated biosensing methods have been developed to detect specific DNA sequences in a separation-free format. Both methods use 2 target-specific oligonucleotide probes to recognize a specific target. The first method is based on cross-linking of 2 QDs with distinct emission wavelengths caused by probe-target ... More
Homogenous rapid detection of nucleic acids using two-color quantum dots.
AuthorsZhang CY, Johnson LW
JournalAnalyst
PubMed ID16568163
'We report a homogenous method for rapid and sensitive detection of nucleic acids using two-color quantum dots (QDs) based on single-molecule coincidence detection. The streptavidin-coated quantum dots functioned as both a nano-scaffold and as a fluorescence pair for coincidence detection. Two biotinylated oligonucleotide probes were used to recognize and detect ... More
Induction of apoptosis by antisense CK2 in human prostate cancer xenograft model.
AuthorsSlaton JW, Unger GM, Sloper DT, Davis AT, Ahmed K
JournalMol Cancer Res
PubMed ID15634760
'Protein serine/threonine kinase CK2 (formerly casein kinase 2) is a ubiquitous protein kinase that plays key roles in cell growth, proliferation, and survival. We have shown previously that its molecular down-regulation induces apoptosis in cancer cells in culture. Here, we have employed a xenograft model of prostate cancer to extend ... More
Nanoparticles as fluorescence labels: is size all that matters?
AuthorsSwift JL, Cramb DT,
JournalBiophys J
PubMed ID18390610
'Fluorescent labels are often used in bioassays as a means to detect and characterize ligand-receptor binding. This is due in part to the inherently high sensitivity of fluorescence-based technology and the relative accessibility of the technique. There is often little concern raised as to whether or not the fluorescent label ... More
Targeted cellular delivery of quantum dots loaded on and in biotinylated liposomes.
AuthorsSigot V, Arndt-Jovin DJ, Jovin TM,
JournalBioconjug Chem
PubMed ID20715851
'We describe the preparation, biophysical characterization, and receptor-mediated cellular internalization of biotinylated lipid particles (BLPs) loaded on the surface and internally with two distinct (colors) of quantum dot (QD) probes. BLPs were formulated with 1.4 and 2.7 mol % PEG-lipids containing either a fusogenic or pH-sensitive lipid to promote bilayer ... More
Biotin-ligand complexes with streptavidin quantum dots for in vivo cell labeling of membrane receptors.
AuthorsLidke DS, Nagy P, Jovin TM, Arndt-Jovin DJ,
JournalMethods Mol Biol
PubMed ID17237530
'The unique fluorescence properties of quantum dots (QDs), particularly their large extinction coefficients and photostability, make them ideal probes for tracking proteins in live cells using real-time visualization. We have shown that QDs conjugated to epidermal growth factor act as functional ligands for their receptor, erbB1. Here, we describe protocols ... More
Reaching out for signals: filopodia sense EGF and respond by directed retrograde transport of activated receptors.
AuthorsLidke DS, Lidke KA, Rieger B, Jovin TM, Arndt-Jovin DJ
JournalJ Cell Biol
PubMed ID16103229
'ErbB1 receptors situated on cellular filopodia undergo systematic retrograde transport after binding of the epidermal growth factor (EGF) and activation of the receptor tyrosine kinase. Specific inhibitors of the erbB1 receptor tyrosine kinase as well as cytochalasin D, a disruptor of the actin cytoskeleton, abolish transport but not free diffusion ... More
Analysis of UV-excited fluorochromes by flow cytometry using near-ultraviolet laser diodes.
AuthorsTelford WG
JournalCytometry A
PubMed ID15351984
'INTRODUCTION: Violet laser diodes have become common and reliable laser sources for benchtop flow cytometers. While these lasers are very useful for a variety of violet and some ultraviolet-excited fluorochromes (e.g., DAPI), they do not efficiently excite most UV-stimulated probes. In this study, the next generation of InGaN near-UV laser ... More
The development of quantum dot calibration beads and quantitative multicolor bioassays in flow cytometry and microscopy.
AuthorsWu Y, Campos SK, Lopez GP, Ozbun MA, Sklar LA, Buranda T
JournalAnal Biochem
PubMed ID17397793
'The use of fluorescence calibration beads has been the hallmark of quantitative flow cytometry. It has enabled the direct comparison of interlaboratory data as well as quality control in clinical flow cytometry. In this article, we describe a simple method for producing color-generalizable calibration beads based on streptavidin functionalized quantum ... More
Quantum dot self-assembly for protein detection with sub-picomolar sensitivity.
AuthorsSoman CP, Giorgio TD,
JournalLangmuir
PubMed ID18335969
'A novel approach to sensitive and rapid antigen detection is described. In the presence of a specific antigen, quantum dot-antibody conjugates rapidly self-assemble into agglomerates that are typically more than 1 order of magnitude larger than their individual components. The size distribution of the agglomerated colloids depends on, among other ... More
Detection of single bacterial pathogens with semiconductor quantum dots.
AuthorsHahn MA, Tabb JS, Krauss TD
JournalAnal Chem
PubMed ID16053299
'Semiconductor quantum dots (QDs) have been used in a simple fluorometric assay to detect single cells of the pathogenic Escherichia coli O157:H7 serotype. Composed of CdSe/ZnS core/shell QDs conjugated to streptavidin, this system exhibits 2 orders of magnitude more sensitivity than a similar assay using a common organic dye. Selectivity ... More
Flow cytometric analysis to detect pathogens in bacterial cell mixtures using semiconductor quantum dots.
AuthorsHahn MA, Keng PC, Krauss TD,
JournalAnal Chem
PubMed ID18186615
'Compared to a common green organic dye, semiconductor quantum dots (QDs) composed of CdSe/ZnS core/shell bioconjugates display brighter fluorescence intensities, lower detection thresholds, and better accuracy in analyzing bacterial cell mixtures composed of pathogenic E. coli O157:H7 and harmless E. coli DH5alpha using flow cytometry. For the same given bacterial ... More
Method for multiplex cellular detection of mRNAs using quantum dot fluorescent in situ hybridization.
'The photostability and narrow emission spectra of non-organic quantum dot fluorophores (QDs) make them desirable candidates for fluorescent in situ hybridization (FISH) to study the expression of specific mRNA transcripts. We developed a novel method for direct QD labeling of modified oligonucleotide probes through streptavidin and biotin interactions, as well ... More
Progression of respiratory syncytial virus infection monitored by fluorescent quantum dot probes.
AuthorsBentzen EL, House F, Utley TJ, Crowe JE, Wright DW
JournalNano Lett
PubMed ID15826092
We report the use of quantum dots (QDs) to identify the presence and monitor the progression of respiratory syncytial virus (RSV) infection over time by labeling the F and G proteins. In addition, co-localization of these viral proteins was shown using confocal microscopy. The implications of these results are that ... More
Multiplexed hybridization detection with multicolor colocalization of quantum dot nanoprobes.
AuthorsHo YP, Kung MC, Yang S, Wang TH
JournalNano Lett
PubMed ID16159207
We demonstrate a hybridization detection method using multicolor oligonucleotide-functionalized quantum dots as nanoprobes. In the presence of various target sequences, combinatorial self-assembly of the nanoprobes via independent hybridization reactions leads to the generation of discernible sequence-specific spectral codings. Detection of single-molecule hybridization is achieved by measuring colocalization of individual nanoprobes. ... More
A quantum dot-labeled ligand-receptor binding assay for G protein-coupled receptors contained in minimally purified membrane nanopatches.
AuthorsSwift JL, Burger MC, Cramb DT,
JournalMethods Mol Biol
PubMed ID19513661
A robust method to directly measure ligand-receptor binding interactions using fluorescence cross-correlation spectroscopy (FCCS) is described. The example receptor systems demonstrated here are the human micro-opioid receptor, a representative G protein-coupled receptor (GPCR), and Streptavidin, but these general protocols can be extended for the analysis of many membrane receptors. We ... More
Quantum dot hybrid gel blotting: a technique for identifying quantum dot-protein/protein-protein interactions.
AuthorsVu TQ, Liu HY,
JournalMethods Mol Biol
PubMed ID19488713
We describe an alternative to the molecular biology technique of polyacrylamide gel electrophoresis-based Western blotting and immunoprecipitation, which is an extensively used method for separating target proteins from complex cellular mixtures and for identification of protein expression and protein-protein interactions. This novel method, called quantum dot (QD) hybrid gel blotting, ... More
A technical note on quantum dots for multi-color fluorescence in situ hybridization.
AuthorsMüller S, Cremer M, Neusser M, Grasser F, Cremer T,
JournalCytogenet Genome Res
PubMed ID19556786
Quantum dots (Qdots) are semiconductor nanocrystals, which are photo-stable, show bright fluorescence with narrow, symmetric emission spectra and are available in multiple resolvable colors. We established a FISH protocol for the simultaneous visualization of up to 6 different DNA probes differentially labeled with Qdots and with conventional organic fluorochromes. Using ... More
Aging and cytomegalovirus infection differentially and jointly affect distinct circulating T cell subsets in humans.
AuthorsWertheimer AM, Bennett MS, Park B, Uhrlaub JL, Martinez C, Pulko V, Currier NL, Nikolich-Žugich D, Kaye J, Nikolich-Žugich J
Journal
PubMed ID24501199
The impact of intrinsic aging upon human peripheral blood T cell subsets remains incompletely quantified and understood. This impact must be distinguished from the influence of latent persistent microorganisms, particularly CMV, which has been associated with age-related changes in the T cell pool. In a cross-sectional cohort of 152 CMV-negative ... More
Spectroscopic characterization of streptavidin functionalized quantum dots.
AuthorsWu Y, Lopez GP, Sklar LA, Buranda T
JournalAnal Biochem
PubMed ID17368555
The spectroscopic properties of quantum dots can be strongly influenced by the conditions of their synthesis. In this work, we have characterized several spectroscopic properties of commercial, streptavidin functionalized quantum dots (QD525, lot 1005-0045, and QD585, lot 0905-0031, from Invitrogen). This is the first step in the development of calibration ... More
Optimized linkage and quenching strategies for quantum dot molecular beacons.
AuthorsCady NC, Strickland AD, Batt CA
JournalMol Cell Probes
PubMed ID17084590
Quantum dot (QD) molecular beacons were explored for sequence-specific DNA detection. The effectiveness of multiple linkage strategies and fluorescence quenchers were compared in hybridization-based assays. To compare linkage strategies, covalent amide linkage and streptavidin-biotin binding were used to link semiconductor QDs to molecular beacon DNA. Amide-linked beacons showed a 57% ... More
Multispectral imaging of clinically relevant cellular targets in tonsil and lymphoid tissue using semiconductor quantum dots.
AuthorsFountaine TJ, Wincovitch SM, Geho DH, Garfield SH, Pittaluga S
JournalMod Pathol
PubMed ID16778828
Determination of the expression and spatial distribution of molecular epitopes, or antigens, in patient tissue specimens has substantially improved the pathologist's ability to classify disease processes. Certain disease pathophysiologies are marked by characteristic increased or decreased expression of developmentally controlled antigens, defined as Cluster of Differentiation markers, that currently form ... More
A two-photon excitation fluorescence cross-correlation assay for a model ligand-receptor binding system using quantum dots.
AuthorsSwift JL, Heuff R, Cramb DT
JournalBiophys J
PubMed ID16299079
Two-photon excitation fluorescence cross-correlation spectroscopy (TPE-XCS) is a very suitable method for studying interactions of two distinctly labeled fluorescent molecules. As such, it lends itself nicely to the study of ligand-receptor interactions. By labeling the ligand with one color of fluorescent dye and the receptor with another, it is possible ... More
Analysis of CD36 expression on human monocytic cells and atherosclerotic tissue sections with quantum dots: investigation by flow cytometry and spectral imaging microscopy.
AuthorsKahn E, Vejux A, Ménétrier F, Maiza C, Hammann A, Sequeira-Le Grand A, Frouin F, Tourneur Y, Brau F, Riedinger JM, Steinmetz E, Todd-Pokropek A, Lizard G
JournalAnal Quant Cytol Histol
PubMed ID16566276
OBJECTIVE: To demonstrate CD36 expression with quantum dots (QDs) 525 and/or 605 on human monocytic U937 cells and atherosclerotic tissue sections by means of flow cytometry (FCM) and/or confocal laser scanning microscopy (CLSM). STUDY DESIGN: U937 cells and tissue sections were analyzed by means of FCM and/or CLSM. FCM was ... More