Random walk of processive, quantum dot-labeled myosin Va molecules within the actin cortex of COS-7 cells.
AuthorsNelson SR, Ali MY, Trybus KM, Warshaw DM,
JournalBiophys J
PubMed ID19619465
'Myosin Va (myoVa) is an actin-based intracellular cargo transporter. In vitro experiments have established that a single myoVa moves processively along actin tracks, but less is known about how this motor operates within cells. Here we track the movement of a quantum dot (Qdot)-labeled myoVa HMM in COS-7 cells using ... More
The human herpesvirus 8 chemokine receptor vGPCR triggers autonomous proliferation of endothelial cells.
AuthorsGrisotto MG, Garin A, Martin AP, Jensen KK, Chan P, Sealfon SC, Lira SA
JournalJ Clin Invest
PubMed ID16604194
'We have used a novel conditional transgenic system to study the mechanisms of angioproliferation induced by viral G protein-coupled receptor (vGPCR), the constitutively active chemokine receptor encoded by human herpesvirus 8 (HHV8, also known as Kaposi sarcoma herpesvirus). Using this system, we were able to control temporal expression of vGPCR ... 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
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
Suppressing Brownian motion of individual biomolecules in solution.
AuthorsCohen AE, Moerner WE
JournalProc Natl Acad Sci U S A
PubMed ID16537418
'Single biomolecules in free solution have long been of interest for detailed study by optical methods, but Brownian motion prevents the observation of one single molecule for extended periods. We have used an anti-Brownian electrokinetic (ABEL) trap to trap individual protein molecules in free solution, under ambient conditions, without requiring ... 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 dots--a versatile tool in plant science?
AuthorsMüller F, Houben A, Barker PE, Xiao Y, Käs JA, Melzer M
JournalJ Nanobiotechnology
PubMed ID16776835
An optically stable, novel class of fluorophores (quantum dots) for in situ hybridisation analysis was tested to investigate their signal stability and intensity in plant chromosome analyses. Detection of hybridisation sites in situ was based on fluorescence from streptavidin-linked inorganic crystals of cadmium selenide. Comparison of quantum dots (QDs) with ... More
Bioconjugation of quantum dot luminescent probes for Western blot analysis.
AuthorsMakrides SC, Gasbarro C, Bello JM
JournalBiotechniques
PubMed ID16235562
Western blot analysis is a widely used technique for protein immunodetection. Its current format, however is unsuitable for multiplex detection of proteins, primarily due to intrinsic limitations of standard organic dyes employed as probes. Quantum dot (QD) semiconductor nanoparticles exhibit significant advantages over organic dyes, including their broad absorption bands, ... More
Differential labeling of myosin V heads with quantum dots allows direct visualization of hand-over-hand processivity.
AuthorsWarshaw DM, Kennedy GG, Work SS, Krementsova EB, Beck S, Trybus KM
JournalBiophys J
PubMed ID15764654
The double-headed myosin V molecular motor carries intracellular cargo processively along actin tracks in a hand-over-hand manner. To test this hypothesis at the molecular level, we observed single myosin V molecules that were differentially labeled with quantum dots having different emission spectra so that the position of each head could ... 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
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
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