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Reporter Molecules (reporter + molecule)
Selected AbstractsTriplex Au,Ag,C Core,Shell Nanoparticles as a Novel Raman LabelADVANCED FUNCTIONAL MATERIALS, Issue 6 2010Aiguo Shen Abstract Monodispersed, readily-grafted, and biocompatible surface-enhanced Raman spectroscopic (SERS) tagging materials are developed; they are composed of bimetallic Au@Ag nanoparticles (NPs) for optical enhancement, a reporter molecule for spectroscopic signature, and a carbon shell for protection and bioconjugation. A controllable and convenient hydrothermal synthetic route is presented to synthesize the layer-by-layer triplex Au,Ag,C core,shell NPs, which can incorporate the Raman-active label 4-mercapto benzoic acid (4-MBA). The obtained gold seed,silver coated particles can be coated further with a thickness-controlled carbon shell to form colloidal carbon-encapsulated Aucore/Agshell spheres with a monodisperse size distribution. Furthermore, these SERS-active spheres demonstrated interesting properties as a novel Raman tag for quantitative immunoassays. The results suggest such SERS tags can be used for multiplex and ultrasensitive detection of biomolecules as well as nontoxic, in vivo molecular imaging of animal or plant tissues. [source] Medium-sized peptides as built in carriers for biologically active compoundsMEDICINAL RESEARCH REVIEWS, Issue 6 2005Ferenc Hudecz Abstract A growing number of oligopeptides of natural and/or synthetic origin have been described and considered as targeting structures for delivery bioactive compounds into various cell types. This review will outline the discovery of peptide sequences and the corresponding mid-sized oligopeptides with membrane translocating properties and also summarize de novo designed structures possessing similar features. Conjugates and chimera constructs derived from these sequences with covalently attached bioactive peptide, epitope, oligonucleotide, PNA, drug, reporter molecule will be reviewed. A brief note will refer to the present understanding on the uptake mechanism at the end of each section. © 2005 Wiley Periodicals, Inc. Med Res Rev [source] Flow cytometry-assisted purification and proteomic analysis of the corticotropes dense-core secretory granulesPROTEINS: STRUCTURE, FUNCTION AND BIOINFORMATICS, Issue 18 2008Daniel J. Gauthier Abstract The field of organellar proteomics has emerged as an attempt to minimize the complexity of the proteomics data obtained from whole cell and tissue extracts while maximizing the resolution on the protein composition of a single subcellular compartment. Standard methods involve lengthy density-based gradient and/or immunoaffinity purification steps followed by extraction, 1-DE or 2-DE, gel staining, in-gel tryptic digestion, and protein identification by MS. In this paper, we present an alternate approach to purify subcellular organelles containing a fluorescent reporter molecule. The gel-free procedure involves fluorescence-assisted sorting of the secretory granules followed by gentle extraction in a buffer compatible with tryptic digestion and MS. Once the subcellular organelle labeled, this procedure can be done in a single day, requires no major modification to any instrumentation and can be readily adapted to the study of other organelles. When applied to corticotrope secretory granules, it led to a much enriched granular fraction from which numerous proteins could be identified through MS. [source] An alternative method for delivering exogenous material into developing zebrafish embryosBIOTECHNOLOGY & BIOENGINEERING, Issue 6 2007Vikram Kohli Abstract Non-invasive manipulation of multicellular systems is important for medical and biological research. The ability to introduce, remove, or modify molecules in the intracellular environment is pivotal to our understanding of cellular structure and function. Herein, we report on an alternative method for introducing foreign material into developing embryos using the application of femtosecond (fs) laser pulses. When intense fs laser pulses are focused to a sub-micron spot, transient pores are formed, providing a transport pathway for the delivery of exogenous material into embryonic cells. In this study, zebrafish embryos were used as a model system to demonstrate the non-invasiveness of this applied delivery tool. Utilizing optically induced transient pores chorionated and dechorionated zebrafish embryos were successfully loaded with a fluorescent reporter molecule (fluorescein isothiocyanate), Streptavidin-conjugated quantum dots or DNA (Simian-CMV-EGFP). Pore formation was independent of the targeted location, with both blastomere-yolk interface and blastomere pores competent for delivery. Long-term survival of laser manipulated embryos to pec-fin stage was 89% and 100% for dechorionated and chorionated embryos, respectively. To our knowledge, this is the first report of DNA delivery into zebrafish embryos utilizing fs laser pulses. Biotechnol. Bioeng. 2007;98: 1230,1241. © 2007 Wiley Periodicals, Inc. [source] Oligonucleotides Containing 7-Deaza-2,-deoxyinosine as Universal Nucleoside: Synthesis of 7-Halogenated and 7-Alkynylated Derivatives, Ambiguous Base Pairing, and Dye Functionalization by the Alkyne,Azide ,Click' ReactionHELVETICA CHIMICA ACTA, Issue 7 2008Frank Seela Abstract Oligonucleotides containing 7-deaza-2,-deoxyinosine derivatives bearing 7-halogen substituents or 7-alkynyl groups were prepared. For this, the phosphoramidites 2b,2g containing 7-substituted 7-deaza-2,-deoxyinosine analogues 1b,1g were synthesized (Scheme,2). Hybridization experiments with modified oligonucleotides demonstrate that all 2,-deoxyinosine derivatives show ambiguous base pairing, as 2,-deoxyinosine does. The duplex stability decreases in the order Cd>Ad>Td>Gd when 2b,2g pair with these canonical nucleosides (Table,6). The self-complementary duplexes 5,-d(F7c7I-C)6, d(Br7c7I-C)6, and d(I7c7I-C)6 are more stable than the parent duplex d(c7I-C)6 (Table,7). An oligonucleotide containing the octa-1,7-diyn-1-yl derivative 1g, i.e., 27, was functionalized with the nonfluorescent 3-azido-7-hydroxycoumarin (28) by the Huisgen,Sharpless,Meldal cycloaddition ,click' reaction to afford the highly fluorescent oligonucleotide conjugate 29 (Scheme,3). Consequently, oligonucleotides incorporating the derivative 1g bearing a terminal CC bond show a number of favorable properties: i) it is possible to activate them by labeling with reporter molecules employing the ,click' chemistry. ii) Space demanding residues introduced in the 7-position of the 7-deazapurine base does not interfere with duplex structure and stability (Table,8). iii) The ambiguous pairing character of the nucleobase makes them universal probes for numerous applications in oligonucleotide chemistry, molecular biology, and nanobiotechnology. [source] Cellular transport strategies for targeting epitopes, drugs and reporter moleculesJOURNAL OF MOLECULAR RECOGNITION, Issue 5 2003Ferenc Hudecz Workshop Chairman [source] Protein adsorption drastically reduces surface-enhanced Raman signal of dye moleculesJOURNAL OF RAMAN SPECTROSCOPY, Issue 9 2010Dongmao Zhang Abstract There is an increasing interest in developing surface enhancement Raman spectroscopy methods for intracellular biomolecule and for in vitro protein detection that involve dye or protein,dye conjugates. In this work, we have demonstrated that protein adsorption on silver nanoparticle (AgNP) can significantly attenuate the surface-enhanced Raman spectroscopy (SERS) signal of dye molecules in both protein/dye mixtures and protein/dye conjugates. SERS spectra of 12 protein/dye mixtures were acquired using 4 proteins [bovine serum albumin (BSA), lysozyme, trypsin, and concanavalin A] and three dyes [Rhodamine 6G, adenine, and fluorescein isothiocyanate (FITC)]. Besides the protein/dye mixtures, spectra were also obtained for the free dyes and four FITC-conjugated proteins. While no SERS signal was observed in protein/FITC mixtures or conjugates, a significantly reduced SERS intensity (up to 3 orders of magnitude) was observed for both R6G and adenine in their respective protein mixtures. Quantitative estimation of the number of dye molecules absorbed onto AgNP implied that the degree of R6G SERS signal reduction in the R6G/BSA sample is 2 to 3 orders of magnitude higher than what could be accounted for by the difference in the amount of the absorbed dyes. This finding has significant implications for both intracellular SERS analyses and in vitro protein detection using SERS tagging strategies that rely on Raman dyes as reporter molecules. Copyright © 2009 John Wiley & Sons, Ltd. [source] Optical probing and imaging of live cells using SERS labelsJOURNAL OF RAMAN SPECTROSCOPY, Issue 1 2009Janina Kneipp Abstract During surface-enhanced Raman scattering (SERS), molecules exhibit a significant increase in their Raman signals when attached, or in very close vicinity, to gold or silver nanostructures. This effect is exploited as the basis of a new class of optical labels. Here we demonstrate robust and sensitive SERS labels as probes for imaging live cells. These hybrid labels consist of gold nanoparticles with Rose Bengal or Crystal Violet attached as reporter molecules. These new labels are stable and nontoxic, do not suffer from photobleaching, and can be excited at any excitation wavelength, even in the near infrared. SERS labels can be detected and imaged through the specific Raman signatures of the reporters. In addition, surface-enhanced Raman spectroscopy in the local optical fields of the gold nanoparticles also provides sensitive information on the immediate molecular environment of the label in the cell and allows imaging of the native constituents of the cell. This is demonstrated by images based on a characteristic Raman line of the reporter as well as by displaying lipids based on the SERS signal of the CH deformation/bending modes at ,1470 cm,1. Copyright © 2008 John Wiley & Sons, Ltd. [source] Understanding the key factors for enzymatic conversion of pretreated lignocellulose by partial least square analysisBIOTECHNOLOGY PROGRESS, Issue 2 2010Renliang Huang Abstract The relationship between the physicochemical properties of lignocellulosic substrates and enzyme digestion is still not well known. After different pretreatments, cellulase hydrolysis and measurements of physicochemical characteristics by column solute exclusion, particle size analysis, X-ray diffraction, Fourier transform infrared spectroscopy and solid state 13C nuclear magnetic resonance were performed in this study. Partial least squares was then applied to seek the key factors limiting the rate and extent of cellulose digestion. According to the PLS results, the most important factor for cellulose digestion was accessible interior surface area, followed by delignification and the destruction of the hydrogen bonds. The cellulose digestion at 2 and 24 hr were improved with the increased accessibility of interior surface area to the reporter molecules of 5.1-nm diameter. Removal of lignin and breaking of hydrogen bonds were also found to significantly promote cellulose conversion. Other properties, including the breakdown of intramolecular hydrogen bonds, cellulose crystallinity, and hemicellulose content, had less effect on the efficiency of enzymatic hydrolysis. © 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2010 [source] Preferred Functionalization of Metallic and Small-Diameter Single-Walled Carbon Nanotubes by Nucleophilic Addition of Organolithium and -Magnesium Compounds Followed by ReoxidationCHEMISTRY - A EUROPEAN JOURNAL, Issue 5 2008David Wunderlich Dipl.-Chem Abstract Covalent sidewall addition to single-walled nanotubes (SWNTs) of a series of organolithium and organomagnesium compounds (nBuLi, tBuLi, EtLi, nHexLi, nBuMgCl, tBuMgCl) followed by reoxidation is reported. The functionalized Rn -SWNTs were characterized by Raman and NIR emission spectroscopy. The reaction of SWNTs with organolithium and magnesium compounds exhibits pronounced selectivity: in general, metallic tubes are more reactive than semiconducting ones. The reactivity of SWNTs toward the addition of organometallic compounds is inversely proportional to the diameter of the tubes. This was determined simultaneously and independently for both metallic and semiconducting SWNTs. The reactivity also depends on the steric demands of the addend. Binding of the bulky t- butyl addend is less favorable than addition of primary alkyl groups. Significantly, although tBuLi is less reactive than, for example, nBuLi, it is less selective toward the preferred reaction with metallic tubes. This unexpected behavior is explained by fast electron transfer to the metallic SWNTs having low-lying electronic states close to the Fermi level, a competitive initial process. The NIR emission of weakly functionalized semiconducting SWNTs, also reported for the first time, implies interesting applications of functionalized tubes as novel fluorescent reporter molecules. [source] | |||||||||||||