Tracking of quantum dot-labeled CFTR shows near immobilization by C-terminal PDZ interactions.
AuthorsHaggie PM, Kim JK, Lukacs GL, Verkman AS
JournalMol Biol Cell
PubMed ID16987954
'Mutations in cystic fibrosis transmembrane conductance regulator (CFTR), a cAMP-regulated chloride channel, cause cystic fibrosis. To investigate interactions of CFTR in living cells, we measured the diffusion of quantum dot-labeled CFTR molecules by single particle tracking. In multiple cell lines, including airway epithelia, CFTR diffused little in the plasma membrane, ... More
Targeting quantum dots to surface proteins in living cells with biotin ligase.
AuthorsHowarth M, Takao K, Hayashi Y, Ting AY
JournalProc Natl Acad Sci U S A
PubMed ID15897449
'Escherichia coli biotin ligase site-specifically biotinylates a lysine side chain within a 15-amino acid acceptor peptide (AP) sequence. We show that mammalian cell surface proteins tagged with AP can be biotinylated by biotin ligase added to the medium, while endogenous proteins remain unmodified. The biotin group then serves as a ... More
Semiconductor nanocrystal conjugates, FISH and pH.
AuthorsXiao Y, Telford WG, Ball JC, Locascio LE, Barker PE
JournalNat Methods
PubMed ID16179915
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
Visualizing the endocytosis of phenylephrine in living cells by quantum dot-based tracking.
AuthorsMa J, Wu L, Hou Z, Song Y, Wang L, Jiang W,
Journal
PubMed ID24855959
'To study the intracellular receptor-drug transportation, a fluorescent probe consisting of phenylephrine-polyethylene glycol-quantum dots conjugate was employed to track endocytosis process of phenylephrine in living cells. This type of movement was studied by continuously filming fluorescent images in the same cell. We also calculated the movement parameters, and divided the ... 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
A novel high throughput quantum dot-based fluorescence assay for quantitation of virus binding and attachment.
'Quantum dots (QDots) are fluorescent semiconductor nanocrystals with a narrow emission spectrum, high quantum yield, and excellent photostability. These unique properties of QDots have been utilized to develop a fluorescent binding assay using biotinylated human T cell leukemia virus type 1 (biot-HTLV-1) conjugated with streptavidin-coated QDots that enabled both qualitative ... 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
Parallel detection of antigen-specific T-cell responses by multidimensional encoding of MHC multimers.
AuthorsHadrup SR, Bakker AH, Shu CJ, Andersen RS, van Veluw J, Hombrink P, Castermans E, Thor Straten P, Blank C, Haanen JB, Heemskerk MH, Schumacher TN,
JournalNat Methods
PubMed ID19543285
'The use of fluorescently labeled major histocompatibility complex multimers has become an essential technique for analyzing disease- and therapy-induced T-cell immunity. Whereas classical major histocompatibility complex multimer analyses are well-suited for the detection of immune responses to a few epitopes, limitations on human-subject sample size preclude a comprehensive analysis of ... More
Dynamic multiple-target tracing to probe spatiotemporal cartography of cell membranes.
AuthorsSergé A, Bertaux N, Rigneault H, Marguet D,
JournalNat Methods
PubMed ID18604216
'Although the highly dynamic and mosaic organization of the plasma membrane is well-recognized, depicting a resolved, global view of this organization remains challenging. We present an analytical single-particle tracking (SPT) method and tool, multiple-target tracing (MTT), that takes advantage of the high spatial resolution provided by single-fluorophore sensitivity. MTT can ... More
Fluorescent nanocrystals for use in early cervical cancer detection.
AuthorsNida DL, Rahman MS, Carlson KD, Richards-Kortum R, Follen M
JournalGynecol Oncol
PubMed ID16139342
'BACKGROUND: Quantum dots (qdots) are a promising alternative to organic fluorophores for biological imaging. Advantages of quantum dots over organic fluorophores include broad excitation coupled with narrow, tunable emission, high resistance to chemical and metabolic degradation, a higher photobleaching threshold and finally the ability to be modified with a targeting ... 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
Characterization of the functional binding properties of antibody conjugated quantum dots.
AuthorsPathak S, Davidson MC, Silva GA
JournalNano Lett
PubMed ID17536868
'Antibody conjugated quantum dots are an emerging technology for high-resolution labeling of biological systems. In this work we determined the number of functional antibodies (i.e., antibodies that are sterically available for functional binding to target proteins) conjugated to semiconductor quantum dots. This is critical for the interpretation of biological data ... 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
Blinking suppression in CdSe/ZnS single quantum dots by TiO2 nanoparticles.
AuthorsHamada M, Nakanishi S, Itoh T, Ishikawa M, Biju V,
JournalACS Nano
PubMed ID20731430
'The photoluminescence of semiconductor quantum dots and fluorescence of single molecules intermittently turn ON and OFF, a phenomenon referred to as blinking. In quantum dots, blinking occurs as a result of intermittent Auger ionization, which results in the formation of positively charged quantum dots. Due to strong Coulombic interactions, successive ... More
AuthorsSweeney E, Ward TH, Gray N, Womack C, Jayson G, Hughes A, Dive C, Byers R,
JournalBiochem Biophys Res Commun
PubMed ID18621021
'Quantum dots are photostable fluorescent semiconductor nanocrystals possessing wide excitation and bright narrow, symmetrical, emission spectra. These characteristics have engendered considerable interest in their application in multiplex immunohistochemistry for biomarker quantification and co-localisation in clinical samples. Robust quantitation allows biomarker validation, and there is growing need for multiplex staining due ... 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
Semiconductor nanocrystal probes for human metaphase chromosomes.
AuthorsXiao Y, Barker PE
JournalNucleic Acids Res
PubMed ID14960711
'To improve signal stability and quantitation, an optically stable, novel class of fluorophore for hybridization analysis of human metaphase chromosomes is demonstrated. Detection of hybridization sites in situ was based on fluorescence from streptavidin-linked inorganic crystals of cadmium selenide [(CdSe)ZnS]. Fluorescence of nanocrystal fluorophores was significantly brighter and more photostable ... More
Automated four-color analysis of leukocytes by scanning fluorescence microscopy using quantum dots.
AuthorsBocsi J, Lenz D, Mittag A, Varga VS, Molnar B, Tulassay Z, Sack U, Tárnok A
JournalCytometry A
PubMed ID16479596
'BACKGROUND: Scanning fluorescence microscope (SFM) is a new technique for automated motorized microscopes to measure multiple fluorochrome labeled cells (Bocsi et al., Cytometry A 2004, 61:1-8). AIMS: We developed a four-color staining protocol (DNA, CD3, CD4, and CD8) for the lymphocyte phenotyping by SFM. METHODS: Organic (Alexa488, FITC, PE-Alexa610, CyChrom, ... More
Tracking individual proteins in living cells using single quantum dot imaging.
'Single quantum dot imaging is a powerful approach to probe the complex dynamics of individual biomolecules in living systems. Due to their remarkable photophysical properties and relatively small size, quantum dots can be used as ultrasensitive detection probes. They make possible the study of biological processes, both in the membrane ... More
Quantitative in situ detection of phosphoproteins in fixed tissues using quantum dot technology.
AuthorsBodo J, Durkin L, Hsi ED,
JournalJ Histochem Cytochem
PubMed ID19332430
'Detection and quantitation of phosphoproteins (PPs) in fixed tissues will become increasingly important as additional inhibitors of protein kinases enter clinical use and new disease entities are defined by molecular changes affecting PP levels. We characterize fixation conditions suitable for accurate PP quantitation that are achievable in a clinical laboratory ... 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
Quantum dot applications to neuroscience: new tools for probing neurons and glia.
AuthorsPathak S, Cao E, Davidson MC, Jin S, Silva GA
JournalJ Neurosci
PubMed ID16481420
Photodynamics of a single quantum dot: fluorescence activation, enhancement, intermittency, and decay.
AuthorsLee SF, Osborne MA
JournalJ Am Chem Soc
PubMed ID17608479
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
Velocity, processivity, and individual steps of single myosin V molecules in live cells.
AuthorsPierobon P, Achouri S, Courty S, Dunn AR, Spudich JA, Dahan M, Cappello G,
JournalBiophys J
PubMed ID19450497
We report the tracking of single myosin V molecules in their natural environment, the cell. Myosin V molecules, labeled with quantum dots, are introduced into the cytoplasm of living HeLa cells and their motion is recorded at the single molecule level with high spatial and temporal resolution. We perform an ... 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
Mechanochemical delivery and dynamic tracking of fluorescent quantum dots in the cytoplasm and nucleus of living cells.
AuthorsYum K, Na S, Xiang Y, Wang N, Yu MF,
JournalNano Lett
PubMed ID19366190
Studying molecular dynamics inside living cells is a major but highly rewarding challenge in cell biology. We present a nanoscale mechanochemical method to deliver fluorescent quantum dots (QDs) into living cells, using a membrane-penetrating nanoneedle. We demonstrate the selective delivery of monodispersed QDs into the cytoplasm and the nucleus of ... More
Multiplex detection of RNA expression in Drosophila embryos.
AuthorsKosman D, Mizutani CM, Lemons D, Cox WG, McGinnis W, Bier E
JournalScience
PubMed ID15297669
We present a fluorescence-based, multiplex in situ hybridization method that permits the simultaneous detection of five differently labeled antisense RNA probes and up to seven differ-ent transcripts in a single Drosophila embryo. We also show that it should be possible to increase the number of detected transcripts substantially with nascent ... More
Real-time detection of virus particles and viral protein expression with two-color nanoparticle probes.
AuthorsAgrawal A, Tripp RA, Anderson LJ, Nie S
JournalJ Virol
PubMed ID15956604
Respiratory syncytial virus (RSV) mediates serious lower respiratory tract illness in infants and young children and is a significant pathogen of the elderly and immune compromised. Rapid and sensitive RSV diagnosis is important to infection control and efforts to develop antiviral drugs. Current RSV detection methods are limited by sensitivity ... More
Wet electron microscopy with quantum dots.
AuthorsTimp W, Watson N, Sabban A, Zik O, Matsudaira P
JournalBiotechniques
PubMed ID16989089
Wet electron microscopy (EM) is a new imaging method with the potential to allow higher spatial resolution of samples. In contrast to most EM methods, it requires little time to perform and does not require complicated equipment or difficult steps. We used this method on a common murine macrophage cell ... More
Quantitative detection of antibody based on single-molecule counting by total internal reflection fluorescence microscopy with quantum dot labeling.
AuthorsJiang D, Wang L, Jiang W,
JournalAnal Chim Acta
PubMed ID19154814
We presented a sensitive method to quantify antibody based on single-molecule counting by total internal reflection fluorescence microscopy with quantum dot labeling. In this method, the biotinylated monoclonal anti-human IgG molecules were immobilized on the silanized glass substrate surface. By the strong biotin-streptavidin affinity, streptavidin-coated quantum dots were labeled to ... More
Immune complex relay by subcapsular sinus macrophages and noncognate B cells drives antibody affinity maturation.
AuthorsPhan TG, Green JA, Gray EE, Xu Y, Cyster JG,
JournalNat Immunol
PubMed ID19503106
Subcapsular sinus (SCS) macrophages capture antigens from lymph and present them intact for B cell encounter and follicular delivery. However, the properties of SCS macrophages are poorly defined. Here we show SCS macrophage development depended on lymphotoxin-alpha1beta2, and the cells had low lysosomal enzyme expression and retained opsonized antigens on ... More
Three-dimensional imaging of the intracellular localization of growth hormone and prolactin and their mRNA using nanocrystal (Quantum dot) and confocal laser scanning microscopy techniques.
AuthorsMatsuno A, Itoh J, Takekoshi S, Nagashima T, Osamura RY
JournalJ Histochem Cytochem
PubMed ID15995141
Semiconductor nanocrystals (Quantum dots, Qdots) have recently been used in biological research, because they do not fade on exposure to light, and they enable us to obtain multicolor imaging because of a narrow emission peak that can be excited via a single wavelength of light. There have been no reports ... More
A self-assembled quantum dot probe for detecting beta-lactamase activity.
AuthorsXu C, Xing B, Rao J
JournalBiochem Biophys Res Commun
PubMed ID16631595
This communication describes a quantum dot probe that can be activated by a reporter enzyme, beta-lactamase. Our design is based on the principle of fluorescence resonance energy transfer (FRET). A biotinylated beta-lactamase substrate was labeled with a carbocyanine dye, Cy5, and immobilized on the surface of quantum dots through the ... More
MS-qFRET: a quantum dot-based method for analysis of DNA methylation.
AuthorsBailey VJ, Easwaran H, Zhang Y, Griffiths E, Belinsky SA, Herman JG, Baylin SB, Carraway HE, Wang TH,
JournalGenome Res
PubMed ID19443857
DNA methylation contributes to carcinogenesis by silencing key tumor suppressor genes. Here we report an ultrasensitive and reliable nanotechnology assay, MS-qFRET, for detection and quantification of DNA methylation. Bisulfite-modified DNA is subjected to PCR amplification with primers that would differentiate between methylated and unmethylated DNA. Quantum dots are then used ... More
Simple and accurate quantification of quantum dots via single-particle counting.
AuthorsZhang CY, Johnson LW,
JournalJ Am Chem Soc
PubMed ID18311984
Quantification of quantum dots (QDs) is essential to the quality control of QD synthesis, development of QD-based LEDs and lasers, functionalizing of QDs with biomolecules, and engineering of QDs for biological applications. However, simple and accurate quantification of QD concentration in a variety of buffer solutions and in complex mixtures ... More
Quantum dot-insect neuropeptide conjugates for fluorescence imaging, transfection, and nucleus targeting of living cells.
AuthorsBiju V, Muraleedharan D, Nakayama K, Shinohara Y, Itoh T, Baba Y, Ishikawa M,
JournalLangmuir
PubMed ID17718524
We identified an insect neuropeptide, namely, allatostatin 1 from Drosophila melanogaster, that transfects living NIH 3T3 and A431 human epidermoid carcinoma cells and transports quantum dots (QDs) inside the cytoplasm and even the nucleus of the cells. QD-conjugated biomolecules are valuable resources for visualizing the structures and functions of biological ... More
Quantitation of HER2 and telomerase biomarkers in solid tumors with IgY antibodies and nanocrystal detection.
In an effort to improve affinity biomarker validation in fixed patient tissue specimens, we have developed a novel quantum dot-based bioimaging system that utilizes chicken IgY antibody for high sensitivity and specificity relative quantitation of cancer proteins. Monospecific, polyclonal IgYs were generated against human HER2 and telomerase, and analytically validated ... More
IL-2 coordinates IL-2-producing and regulatory T cell interplay.
AuthorsAmado IF, Berges J, Luther RJ, Mailhé MP, Garcia S, Bandeira A, Weaver C, Liston A, Freitas AA,
Journal
PubMed ID24249704
Many species of bacteria use quorum sensing to sense the amount of secreted metabolites and to adapt their growth according to their population density. We asked whether similar mechanisms would operate in lymphocyte homeostasis. We investigated the regulation of the size of interleukin-2 (IL-2)-producing CD4(+) T cell (IL-2p) pool using ... More
Optimized multiparametric immunophenotyping of umbilical cord blood cells by flow cytometry.
AuthorsBasford C, Forraz N, McGuckin C,
JournalNat Protoc
PubMed ID20595961
Umbilical cord blood is a key source of stem cells for transplantation and regenerative medicine. To maximize each cord blood sample, it is important to analyze its cellular populations. Many cord blood banks focus on counts of total nucleated cells and/or cells that carry the CD34 antigen, but this limited ... More
Transcriptional profiling of antigen-dependent murine B cell differentiation and memory formation.
AuthorsBhattacharya D, Cheah MT, Franco CB, Hosen N, Pin CL, Sha WC, Weissman IL,
JournalJ Immunol
PubMed ID17982071
Humoral immunity is characterized by the generation of Ab-secreting plasma cells and memory B cells that can more rapidly generate specific Abs upon Ag exposure than their naive counterparts. To determine the intrinsic differences that distinguish naive and memory B cells and to identify pathways that allow germinal center B ... More
Semiautomated multiplexed quantum dot-based in situ hybridization and spectral deconvolution.
AuthorsByers RJ, Di Vizio D, O'connell F, Tholouli E, Levenson RM, Gossage K, Gossard K, Twomey D, Yang Y, Benedettini E, Rose J, Ligon KL, Finn SP, Golub TR, Loda M,
JournalJ Mol Diagn
PubMed ID17251332
Gene expression profiling has identified several potentially useful gene signatures for predicting outcome or for selecting targeted therapy. However, these signatures have been developed in fresh or frozen tissue, and there is a need to apply them to routinely processed samples. Here, we demonstrate the feasibility of a potentially high-throughput ... More
In situ visualization and dynamics of newly synthesized proteins in rat hippocampal neurons.
AuthorsDieterich DC, Hodas JJ, Gouzer G, Shadrin IY, Ngo JT, Triller A, Tirrell DA, Schuman EM,
JournalNat Neurosci
PubMed ID20543841
Protein translation has been implicated in different forms of synaptic plasticity, but direct in situ visualization of new proteins is limited to one or two proteins at a time. Here we describe a metabolic labeling approach based on incorporation of noncanonical amino acids into proteins followed by chemoselective fluorescence tagging ... More
Endophilin B1 as a novel regulator of nerve growth factor/ TrkA trafficking and neurite outgrowth.
AuthorsWan J, Cheung AY, Fu WY, Wu C, Zhang M, Mobley WC, Cheung ZH, Ip NY,
JournalJ Neurosci
PubMed ID18768694
Neurotrophins and their cognate receptors Trks are important regulators of neuronal survival and differentiation. Recent studies reveal that internalization and trafficking of Trks play a critical role in neurotrophin-mediated signaling. At present, little is known of the molecular events that mediate this process. In the current study, we show that ... More
High-sensitivity bacterial detection using biotin-tagged phage and quantum-dot nanocomplexes.
AuthorsEdgar R, McKinstry M, Hwang J, Oppenheim AB, Fekete RA, Giulian G, Merril C, Nagashima K, Adhya S
JournalProc Natl Acad Sci U S A
PubMed ID16549760
With current concerns of antibiotic-resistant bacteria and biodefense, it has become important to rapidly identify infectious bacteria. Traditional technologies involving isolation and amplification of the pathogenic bacteria are time-consuming. We report a rapid and simple method that combines in vivo biotinylation of engineered host-specific bacteriophage and conjugation of the phage ... More
Quantum dot semiconductor nanocrystals for immunophenotyping by polychromatic flow cytometry.
AuthorsChattopadhyay PK, Price DA, Harper TF, Betts MR, Yu J, Gostick E, Perfetto SP, Goepfert P, Koup RA, De Rosa SC, Bruchez MP, Roederer M
JournalNat Med
PubMed ID16862156
Immune responses arise from a wide variety of cells expressing unique combinations of multiple cell-surface proteins. Detailed characterization is hampered, however, by limitations in available probes and instrumentation. Here, we use the unique spectral properties of semiconductor nanocrystals (quantum dots) to extend the capabilities of polychromatic flow cytometry to resolve ... More
The development of rapid fluorescence-based immunoassays, using quantum dot-labelled antibodies for the detection of Listeria monocytogenes cell surface proteins.
AuthorsTully E, Hearty S, Leonard P, O'Kennedy R
JournalInt J Biol Macromol
PubMed ID16600361
Listeria monocytogenes is an important food-borne pathogen with an extremely high mortality rate (approximately 30%). Therefore, a highly sensitive, reproducible and rapid assay for its detection is vital. L. monocytogenes cells employ two surface bound proteins, Internalin A (InlA) and Internalin B (InlB) to promote invasion into host cells. Recombinant ... More
Quantum dot ligands provide new insights into erbB/HER receptor-mediated signal transduction.
AuthorsLidke DS, Nagy P, Heintzmann R, Arndt-Jovin DJ, Post JN, Grecco HE, Jares-Erijman EA, Jovin TM
JournalNat Biotechnol
PubMed ID14704683
The erbB/HER family of transmembrane receptor tyrosine kinases (RTKs) mediate cellular responses to epidermal growth factor (EGF) and related ligands. We have imaged the early stages of RTK-dependent signaling in living cells using: (i) stable expression of erbB1/2/3 fused with visible fluorescent proteins (VFPs), (ii) fluorescent quantum dots (QDs) bearing ... More
Automated quantification of quantum-dot-labelled epidermal growth factor receptor internalization via multiscale image segmentation.
AuthorsKriete A, Papazoglou E, Edrissi B, Pais H, Pourrezaei K
JournalJ Microsc
PubMed ID16734710
The ability to monitor epidermal growth factor receptor (EGFr) internalization specifically, and cellular protein concentrations and activation states in general, has been recently improved by the use of appropriately functionalized quantum dots (QDs), as a result of the long-lasting fluorescence, brightness and multicolour of these nanoparticles. However, important quantitative information ... More
Detection of single DNA molecules by multicolor quantum-dot end-labeling.
AuthorsCrut A, Géron-Landre B, Bonnet I, Bonneau S, Desbiolles P, Escudé C
JournalNucleic Acids Res
PubMed ID15967805
Observation of DNA-protein interactions by single molecule fluorescence microscopy is usually performed by using fluorescent DNA binding agents. However, such dyes have been shown to induce cleavage of the DNA molecule and perturb its interactions with proteins. A new method for the detection of surface-attached DNA molecules by fluorescence microscopy ... More
Asymmetric redistribution of GABA receptors during GABA gradient sensing by nerve growth cones analyzed by single quantum dot imaging.
AuthorsBouzigues C, Morel M, Triller A, Dahan M
JournalProc Natl Acad Sci U S A
PubMed ID17592112
During development of the nervous system, the tip of a growing axon, the growth cone (GC), must respond accurately to stimuli that direct its growth. This axonal navigation depends on extracellular concentration gradients of numerous guidance cues, including GABA. GCs can detect even weak directional signals, yet the mechanisms underlying ... More
One at a time, live tracking of NGF axonal transport using quantum dots.
AuthorsCui B, Wu C, Chen L, Ramirez A, Bearer EL, Li WP, Mobley WC, Chu S
JournalProc Natl Acad Sci U S A
PubMed ID17698956
Retrograde axonal transport of nerve growth factor (NGF) signals is critical for the survival, differentiation, and maintenance of peripheral sympathetic and sensory neurons and basal forebrain cholinergic neurons. However, the mechanisms by which the NGF signal is propagated from the axon terminal to the cell body are yet to be ... More
Band 3 modifications in Plasmodium falciparum-infected AA and CC erythrocytes assayed by autocorrelation analysis using quantum dots.
The molecular stability of hemoglobin is critical for normal erythrocyte functions, including oxygen transport. Hemoglobin C (HbC) is a mutant hemoglobin that has increased oxidative susceptibility due to an amino acid substitution (beta6: Glu to Lys). The growth of Plasmodium falciparum is abnormal in homozygous CC erythrocytes in vitro, and ... More
Detection and correction of blinking bias in image correlation transport measurements of quantum dot tagged macromolecules.
Semiconductor nanocrystals or quantum dots (QDs) are becoming widely used as fluorescent labels for biological applications. Here we demonstrate that fluorescence fluctuation analysis of their diffusional mobility using temporal image correlation spectroscopy is highly susceptible to systematic errors caused by fluorescence blinking of the nanoparticles. Temporal correlation analysis of fluorescence ... 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
Quantum dots are powerful multipurpose vital labeling agents in zebrafish embryos.
AuthorsRieger S, Kulkarni RP, Darcy D, Fraser SE, Köster RW
JournalDev Dyn
PubMed ID16110511
Recently, inorganic fluorescent contrast agents composed of semiconductor materials have been introduced to biological imaging approaches. These so-called quantum dots provide unique and promising properties unreached by organic fluorophores, but their use as contrast agents within live organisms has been limited, probably due in part to concerns about their in ... More
Application of multiline two-photon microscopy to functional in vivo imaging.
AuthorsKurtz R, Fricke M, Kalb J, Tinnefeld P, Sauer M
JournalJ Neurosci Methods
PubMed ID16442636
High spatial resolution and low risks of photodamage make two-photon laser-scanning microscopy (TPLSM) the method of choice for biological imaging. However, the study of functional dynamics such as neuronal calcium regulation often also requires a high temporal resolution. Hitherto, acquisition speed is usually increased by line scanning, which restricts spatial ... 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
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
Optical imaging of cervical pre-cancers with structured illumination: an integrated approach.
AuthorsRahman M, Abd-El-Barr M, Mack V, Tkaczyk T, Sokolov K, Richards-Kortum R, Descour M
JournalGynecol Oncol
PubMed ID16154624
OBJECTIVE: Structured illumination microscopy is an inexpensive alternative to confocal microscopy that allows optical sectioning at a sub-cellular resolution. However, its application in imaging biological tissue has been limited by inadequate contrast present in them especially in reflectance imaging. Novel, optically active contrast agents like gold nanoparticles and quantum dots ... More