Development of a novel FRET immunosensor technique.
AuthorsLichlyter DJ, Grant SA, Soykan O
JournalBiosens Bioelectron
PubMed ID14611757
'We report on a novel technique to develop an optical immunosensor based on fluorescence resonance energy transfer (FRET). IgG antibodies were labeled with acceptor fluorophores while one of three carrier molecules (protein A, protein G, or F(ab'')2 fragment) was labeled with donor fluorophores. The carrier molecule was incubated with the ... More
Inactivation of NPC1L1 causes multiple lipid transport defects and protects against diet-induced hypercholesterolemia.
AuthorsDavies JP, Scott C, Oishi K, Liapis A, Ioannou YA
JournalJ Biol Chem
PubMed ID15671032
'NPC1L1, a recently identified relative of Niemann-Pick C1, was characterized to determine its subcellular location and potential function(s). NPC1L1 was highly expressed in HepG2 cells and localized in a subcellular vesicular compartment rich in the small GTPase Rab5. mRNA expression profiling revealed significant differences between mouse and man with highest ... More
Fabrication of phospholipid bilayer-coated microchannels for on-chip immunoassays.
AuthorsYang T, Jung S, Mao H, Cremer PS
JournalAnal Chem
PubMed ID11199961
'Herein we describe a new class of microfluidic immunoassays based upon solid supported lipid bilayers. Two-dimensionally fluid bilayer material, which can accommodate multivalent binding between surface-bound ligands and aqueous receptors, was coated on the surface of poly(dimethylsiloxane) microchannels. The bilayers contained dinitrophenyl (DNP)-conjugated lipids for binding with bivalent anti-DNP antibodies. ... More
Alexa dyes, a series of new fluorescent dyes that yield exceptionally bright, photostable conjugates.
AuthorsPanchuk-Voloshina N, Haugland RP, Bishop-Stewart J, Bhalgat MK, Millard PJ, Mao F, Leung WY, Haugland RP
JournalJ Histochem Cytochem
PubMed ID10449539
'Alexa 350, Alexa 430, Alexa 488, Alexa 532, Alexa 546, Alexa 568, and Alexa 594 dyes are a new series of fluorescent dyes with emission/excitation spectra similar to those of AMCA, Lucifer Yellow, fluorescein, rhodamine 6G, tetramethylrhodamine or Cy3, lissamine rhodamine B, and Texas Red, respectively (the numbers in the ... More
Removal of the membrane-anchoring domain of epidermal growth factor leads to intracrine signaling and disruption of mammary epithelial cell organization.
AuthorsWiley HS, Woolf MF, Opresko LK, Burke PM, Will B, Morgan JR, Lauffenburger DA
JournalJ Cell Biol
PubMed ID9832559
'Autocrine EGF-receptor (EGFR) ligands are normally made as membrane-anchored precursors that are proteolytically processed to yield mature, soluble peptides. To explore the function of the membrane-anchoring domain of EGF, we expressed artificial EGF genes either with or without this structure in human mammary epithelial cells (HMEC). These cells require activation ... More
Two-photon fluorescence absorption and emission spectra of dyes relevant for cell imaging.
AuthorsBestvater F, Spiess E, Stobrawa G, Hacker M, Feurer T, Porwol T, Berchner-Pfannschmidt U, Wotzlaw C, Acker H
JournalJ Microsc
PubMed ID12423261
'Two-photon absorption and emission spectra for fluorophores relevant in cell imaging were measured using a 45 fs Ti:sapphire laser, a continuously tuneable optical parametric amplifier for the excitation range 580-1150 nm and an optical multichannel analyser. The measurements included DNA stains, fluorescent dyes coupled to antibodies as well as organelle ... More
The spatial relationship between stem cells and their progeny in the basal layer of human epidermis: a new view based on whole-mount labelling and lineage analysis.
AuthorsJensen UB, Lowell S, Watt FM
JournalDevelopment
PubMed ID10226000
'In order to examine the spatial organisation of stem cells and their progeny in human epidermis, we developed a method for whole-mount epidermal immunofluorescence labelling using high surface beta1 integrin expression as a stem cell marker. We confirmed that there are clusters of high beta1 integrin-expressing cells at the tips ... More
Actin coating of secretory granules during regulated exocytosis correlates with the release of rab3D.
'The present study describes a novel phenomenon in pancreatic acinar cells undergoing regulated exocytosis. When acinar cell preparations were challenged with the secretagogue carbamylcholine, a subpopulation of zymogen granules became coated with filamentous actin. These zymogen granules were always in proximity of the acinar cell apical membrane (the site of ... More
Serodiagnosis of infectious diseases with antigen microarrays.
AuthorsBacarese-Hamilton T, Mezzasoma L, Ardizzoni A, Bistoni F, Crisanti A
JournalJ Appl Microbiol
PubMed ID14678154
'AIMS: To generate protein microarrays by printing microbial antigens on slides to enable the simultaneous determination in human sera of antibodies directed against Toxoplasma gondii, rubella virus, cytomegalovirus and herpes simplex virus (HSV) types 1 and 2. METHODS AND RESULTS: Antigens were printed on activated glass slides using high-speed robotics. ... More
Preparation and characterization of Alexa Fluor 594-labeled epidermal growth factor for fluorescence resonance energy transfer studies: application to the epidermal growth factor receptor.
AuthorsWhitson KB, Beechem JM, Beth AH, Staros JV
JournalAnal Biochem
PubMed ID14690686
'We have prepared and characterized a new fluorescent derivative of murine epidermal growth factor (EGF), Alexa Fluor 594-labeled EGF (A-EGF), for fluorescence studies of EGF-EGF receptor interactions. We describe the synthesis of this derivative and its physical and biological characterization. The significant overlap between the excitation and the emission spectra ... More
Controlled cortical impact traumatic brain injury in 3xTg-AD mice causes acute intra-axonal amyloid-ß accumulation and independently accelerates the development of tau abnormalities.
Alzheimer's disease (AD) is a neurodegenerative disorder characterized pathologically by progressive neuronal loss, extracellular plaques containing the amyloid-ß (Aß) peptides, and neurofibrillary tangles composed of hyperphosphorylated tau proteins. Aß is thought to act upstream of tau, affecting its phosphorylation and therefore aggregation state. One of the major risk factors for ... More
3D-structured illumination microscopy provides novel insight into architecture of human centrosomes.
Centrioles are essential for the formation of cilia and flagella. They also form the core of the centrosome, which organizes microtubule arrays important for cell shape, polarity, motility and division. Here, we have used super-resolution 3D-structured illumination microscopy to analyse the spatial relationship of 18 centriole and pericentriolar matrix (PCM) ... More
Three-dimensional spectral imaging by hadamard transform spectroscopy in a programmable array microscope.
We report the acquisition and deconvolution of three-dimensional spectrally resolved images in a programmable array microscope implementing a Hadamard transform fluorescence spectroscopy system with adjustable spectral resolution. A stack of 16 two-dimensional spectral images was collected at 400 nm intervals along the optical axis. The specimen consisted of a polytene ... More
Simultaneous imaging and functional assessment of cytoskeletal protein connections in passively loaded single muscle cells.
AuthorsShah SB, Lieber RL
JournalJ Histochem Cytochem
PubMed ID12502751
We describe a novel system that permits simultaneous confocal imaging of protein interactions and measurement of cell mechanical properties during passive loading. A mechanical apparatus was designed to replace the stage of a confocal microscope, enabling cell manipulation, force transduction, and imaging. In addition, image processing algorithms were developed to ... More
ErbB-2 amplification inhibits down-regulation and induces constitutive activation of both ErbB-2 and epidermal growth factor receptors.
AuthorsWorthylake R, Opresko LK, Wiley HS
JournalJ Biol Chem
PubMed ID10085130
ErbB-2/HER2 is an important signaling partner for the epidermal growth factor receptor (EGFR). Overexpression of erbB-2 is also associated with poor prognosis in breast cancer. To investigate how erbB-2 amplification affects its interactions with the EGFR, we used a human mammary epithelial cell system in which erbB-2 expression was increased ... More
Real-time imaging of fluorescent flagellar filaments.
AuthorsTurner L, Ryu WS, Berg HC
JournalJ Bacteriol
PubMed ID10781548
Bacteria swim by rotating flagellar filaments that are several micrometers long, but only about 20 nm in diameter. The filaments can exist in different polymorphic forms, having distinct values of curvature and twist. Rotation rates are on the order of 100 Hz. In the past, the motion of individual filaments ... More
The development, maturation, and turnover rate of mouse spleen dendritic cell populations.
AuthorsKamath AT, Pooley J, O'Keeffe MA, Vremec D, Zhan Y, Lew AM, D'Amico A, Wu L, Tough DF, Shortman K
JournalJ Immunol
PubMed ID11120796
Three distinct subtypes of dendritic cells (DC) are present in mouse spleen, separable as CD4(-)8alpha(-), CD4(+)8alpha(-), and CD4(-)8alpha(+) DC. We have tested whether these represent stages of development or activation within one DC lineage, or whether they represent separate DC lineages. All three DC subtypes appear relatively mature by many ... More
Seven-color fluorescence imaging of tissue samples based on Fourier spectroscopy and singular value decomposition.
Seven-color analyses of immunofluorescence-stained tissue samples were accomplished using Fourier spectroscopy-based hyperspectral imaging and singular value decomposition. This system consists of a combination of seven fluorescent dyes, three filtersets, an epifluorescence microscope, a spectral imaging system, a computer for data acquisition, and data analysis software. The spectra of all pixels ... More
Spectral karyotyping combined with locus-specific FISH simultaneously defines genes and chromosomes involved in chromosomal translocations.
AuthorsTonon G, Roschke A, Stover K, Shou Y, Kuehl WM, Kirsch IR
JournalGenes Chromosomes Cancer
PubMed ID10719373
Genes that play roles in malignant transformation have often been found proximate to cancer-associated chromosomal breakpoints. Identifying genes that flank chromosomal reconfigurations is thus essential for cancer cytogenetics. To simplify and expedite this identification, we have developed a novel approach, based on simultaneous spectral karyotyping and fluorescence in situ hybridization ... More
Calcium imaging in live rat optic nerve myelinated axons in vitro using confocal laser microscopy.
AuthorsRen Y, Ridsdale A, Coderre E, Stys PK
JournalJ Neurosci Methods
PubMed ID11040413
Intracellular Ca(2+) plays a major role in the physiological responses of excitable cells, and excessive accumulation of internal Ca(2+) is a key determinant of cell injury and death. Many studies have been carried out on the internal Ca(2+) dynamics in neurons. In constrast, there is virtually no such information for ... More