Simultaneous atomic force microscope and fluorescence measurements of protein unfolding using a calibrated evanescent wave.
AuthorsSarkar A, Robertson RB, Fernandez JM
JournalProc Natl Acad Sci U S A
PubMed ID15326308
Fluorescence techniques for monitoring single-molecule dynamics in the vertical dimension currently do not exist. Here we use an atomic force microscope to calibrate the distance-dependent intensity decay of an evanescent wave. The measured evanescent wave transfer function was then used to convert the vertical motions of a fluorescent particle into ... More
Correlated light and electron microscopic imaging of multiple endogenous proteins using Quantum dots.
AuthorsGiepmans BN, Deerinck TJ, Smarr BL, Jones YZ, Ellisman MH
JournalNat Methods
PubMed ID16179920
'The importance of locating proteins in their context within cells has been heightened recently by the accomplishments in molecular structure and systems biology. Although light microscopy (LM) has been extensively used for mapping protein localization, many studies require the additional resolution of the electron microscope. Here we report the application ... More
Quantum-dot aptamer beacons for the detection of proteins.
AuthorsLevy M, Cater SF, Ellington AD
JournalChembiochem
PubMed ID16254932
Combined tyramide signal amplification and quantum dots for sensitive and photostable immunofluorescence detection.
AuthorsNess JM, Akhtar RS, Latham CB, Roth KA
JournalJ Histochem Cytochem
PubMed ID12871979
Conventional immunofluorescence detection of biologically relevant proteins and antigens in tissue sections is often limited by relatively weak signals that fade rapidly on illumination. We have developed an immunohistochemical protocol that combines the sensitivity of tyramide signal amplification with the photostability of quantum dots to overcome these limitations. This simple ... More
Ensemble and single particle photophysical properties (two-photon excitation, anisotropy, FRET, lifetime, spectral conversion) of commercial quantum dots in solution and in live cells.
In this work, we characterized streptavidin-conjugated quantum dots (QDs) manufactured by Quantum Dot Corporation. We present data on: (1) two-photon excitation; (2) fluorescence lifetimes; (3) ensemble and single QD emission anisotropy; (4) QDs as donors for Forster resonance energy transfer (FRET); and (5) spectral conversion of QDs exposed to high-intensity ... 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
Blinking and nonradiant dark fraction of water-soluble quantum dots in aqueous solution.
Water-soluble quantum dots (qdots) are now being used in life sciences research to take advantage of their bright, easily excited fluorescence and high photostability. Although the frequent erratic blinking and substantial dark (never radiant) fractions that occur in all available qdots may interfere with many applications, these properties of individual ... More
NeutrAvidin Functionalization of CdSe/CdS Quantum Nanorods and Quantification of Biotin Binding Sites using Biotin-4-Fluorescein Fluorescence Quenching.
We developed methods to solubilize, coat, and functionalize with NeutrAvidin elongated semiconductor nanocrystals (quantum nanorods, QRs) for use in single molecule polarized fluorescence microscopy. Three different ligands were compared with regard to efficacy for attaching NeutrAvidin using the "zero-length cross-linker" 1-ethyl-3-[3-(dimethylamino)propyl]carbodiimide (EDC). Biotin-4-fluorescene (B4F), a fluorophore that is quenched when ... More