The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Hansachim Wagenknecht - One of the best experts on this subject based on the ideXlab platform.
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Thiazole Orange dimers in dna fluorescent base substitutions with hybridization readout
Chemistry: A European Journal, 2016Co-Authors: Sina Berndl, Hansachim Wagenknecht, Stoichko D Dimitrov, Florian Menacher, Torsten FiebigAbstract:By using (S)-2-amino-1,3-propanediol as a linker, Thiazole Orange (TO) was incorporated in a dimeric form into DNA. The green fluorescence (λ=530 nm) of the intrastrand TO dimer is quenched, whereas the interstrand TO dimer shows a characteristic redshifted Orange emission (λ=585 nm). Steady-state optical spectroscopic methods reveal that the TO dimer fluorescence is independent of the sequential base contexts. Time-resolved pump-probe measurements and excitation spectra reveal the coexistence of conformations, including mainly stacked TO dimers and partially unstacked ones, which yield exciton and excimer contributions to the fluorescence, respectively. The helicity of the DNA framework distorts the excitonic coupling. In particular, the interstrand TO dimer could be regarded as an excitonically interacting base pair with fluorescence readout for DNA hybridization. Finally, the use of this fluorescent readout was representatively demonstrated in molecular beacons.
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imaging of rna delivery to cells by Thiazole Orange as a fluorescent rna base substitution
Organic and Biomolecular Chemistry, 2010Co-Authors: Sina Berndl, Miriam Breunig, Achim Gopferich, Hansachim WagenknechtAbstract:Interstrand Thiazole Orange (TO) dimers in RNA show a yellow colored emission that can be distinguished from the green TO monomer emission by confocal microscopy inside CHO cells.
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fluorescent color readout of dna hybridization with Thiazole Orange as an artificial dna base
Angewandte Chemie, 2009Co-Authors: Sina Berndl, Hansachim WagenknechtAbstract:A fluorescent chameleon: A single Thiazole Orange (TO) dye, when used as an artificial DNA base shows the typical green emission, whereas the interstrand TO dimer exhibits an Orange excimer-type emission inside duplex DNA (see picture).
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Thiazole Orange and cy3 improvement of fluorescent dna probes with use of short range electron transfer
Journal of Organic Chemistry, 2008Co-Authors: Florian Menacher, Sina Berndl, Moritz Rubner, Hansachim WagenknechtAbstract:Thiazole Orange was synthetically incorporated into oligonucleotides by using the corresponding phosphoramidite as the building block for automated DNA synthesis. Due to the covalent fixation of the TO dye as a DNA base surrogate, the TO-modified oligonucleotides do not exhibit a significant increase of fluorescence upon hybridization with the counterstrand. However, if 5-nitroindole (NI) is present as a second artificial DNA base (two base pairs away from the TO dye) a fluorescence increase upon DNA hybridization can be observed. That suggests that a short-range photoinduced electron transfer causes the fluorescence quenching in the single strand. The latter result represents a concept that can be transferred to the commercially available Cy3 label. It enables the Cy3 fluorophore to display the DNA hybridization by a fluorescence increase that is normally not observed with this dye.
Cheukfai Chow - One of the best experts on this subject based on the ideXlab platform.
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boosting the turn on fluorescent signaling ability of Thiazole Orange dyes the effectiveness of structural modification site and its unusual interaction behavior with nucleic acids
Dyes and Pigments, 2018Co-Authors: Wei Long, Jin-qiang Hou, Kun Zhang, Xuanhe Huang, Senyuan Cai, Leonard G Luyt, Wingleung Wong, Cheukfai ChowAbstract:Abstract New fluorescent dyes derivatized on a classical Thiazole Orange framework are able to show unexpectedly strong interaction signal and unusual binding selectivity with different structures of nucleic acid, particularly when bound with double-stranded DNA or G-quadruplex DNA. The present study reveals that these small binding ligands simply bearing an additional amino side group on its parent molecule of Thiazole Orange have almost no background fluorescence in solution. Conversely, they are able to produce an extremely strong yellow emission signal upon interaction with targeting nucleic acids in live cells. The induced fluorescence intensity was approximately 10–15 times stronger than that of Thiazole Orange. The dyes are therefore excellent fluorescent stains for bio-sensing and bio-imaging applications. It is particularly suitable for fluorescence microscopy experiments requiring very low working concentration (0.25 μM or less) targeting nucleic acids. This was demonstrated using pu27 G-quadruplex DNA, which has a low limit of detection (LOD = 3–4 nM) while Thiazole Orange was much higher (LOD = 48.7 nM) under the same conditions. In addition, it was found that structural modification on the quinolinium scaffold of Thiazole Orange was less effective than modification on the benzoThiazole moiety. The findings of the present study provide important information for structural advancement of small molecules based on the widely used Thiazole Orange skeleton, resulting in analogues that are able to achieve higher sensitivity and selectivity for targeting at a specific class of nucleic acids. Computational docking studies were also conducted to illustrate the interaction behaviors of the dyes with different DNA structures.
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molecular engineering of Thiazole Orange dye change of fluorescent signaling from universal to specific upon binding with nucleic acids in bioassay
ACS Chemical Biology, 2016Co-Authors: Qiang Deng, Jin-qiang Hou, Kun Zhang, Leonard G Luyt, Wingleung Wong, Zhengya Wang, Cheukfai ChowAbstract:The universal fluorescent staining property of Thiazole Orange (TO) dye was adapted in order to be specific for G-quadruplex DNA structures, through the introduction of a styrene-like substituent at the ortho-position of the TO scaffold. This extraordinary outcome was determined from experimental studies and further explored through molecular docking studies. The molecular docking studies help understand how such a small substituent leads to remarkable fluorescent signal discrimination between G-quadruplex DNA and other types of nucleic acids. The results reveal that the modified dyes bind to the G-quadruplex or duplex DNA in a similar fashion as TO, but exhibit either enhanced or quenched fluorescent signal, which is determined by the spatial length and orientation of the substituent and has never been known. The new fluorescent dye modified with a p-(dimethylamino)styryl substituent offers 10-fold more selectivity toward telomeric G-quadruplexes than double-stranded DNA substrates. In addition, native PAGE experiments, FRET, CD analysis, and live cell imaging were also studied and demonstrated the potential applications of this class of Thiazole-Orange-based fluorescent probes in bioassays and cell imaging.
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molecular engineering of Thiazole Orange dye change of fluorescent signaling from universal to specific upon binding with nucleic acids in bioassay
ACS Chemical Biology, 2016Co-Authors: Qiang Deng, Jin-qiang Hou, Kun Zhang, Leonard G Luyt, Wingleung Wong, Zhengya Wang, Cheukfai ChowAbstract:The universal fluorescent staining property of Thiazole Orange (TO) dye was adapted in order to be specific for G-quadruplex DNA structures, through the introduction of a styrene-like substituent at the ortho-position of the TO scaffold. This extraordinary outcome was determined from experimental studies and further explored through molecular docking studies. The molecular docking studies help understand how such a small substituent leads to remarkable fluorescent signal discrimination between G-quadruplex DNA and other types of nucleic acids. The results reveal that the modified dyes bind to the G-quadruplex or duplex DNA in a similar fashion as TO, but exhibit either enhanced or quenched fluorescent signal, which is determined by the spatial length and orientation of the substituent and has never been known. The new fluorescent dye modified with a p-(dimethylamino)styryl substituent offers 10-fold more selectivity toward telomeric G-quadruplexes than double-stranded DNA substrates. In addition, native P...
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a molecular fluorescent dye for specific staining and imaging of rna in live cells a novel ligand integration from classical Thiazole Orange and styryl compounds
Chemical Communications, 2015Co-Authors: Qiang Deng, Kun Zhang, Wingleung Wong, Zhengya Wang, Baohua Huang, Yanxiong Fang, Cheukfai ChowAbstract:A new RNA-selective fluorescent dye integrated with a Thiazole Orange and a p-(methylthio)styryl moiety shows better nucleolus RNA staining and imaging performance in live cells than the commercial stains. It also exhibits excellent photostability, cell tolerance, and counterstain compatibility with 4′,6-diamidino-2-phenylindole for specific RNA–DNA colocalization in bioassays.
Xuening Fei - One of the best experts on this subject based on the ideXlab platform.
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synthesis characterization and protein labeling of difunctional magnetic nanoparticles modified with Thiazole Orange dye
Journal of Nanoparticle Research, 2014Co-Authors: Xuening Fei, Huifang Zhu, Jianguo ZhouAbstract:A dual functional nanoparticle was designed and synthesized by encapsulating magnetic core inside silica particles and subsequently a Thiazole Orange (TO) dye derivative was modified on the surface of the nanoparticles. The obtained particles were characterized by Fourier transform infrared spectroscope, Uv–Vis spectrophotometer, fluorescence spectrophotometer, transmission electron microscope, dynamic light scattering, etc. The size of preliminary magnetic particles is ca. 7 nm, but after coating a silica layer and dye, the size of particles is increased to ca. 60 nm. The hydrodynamic diameter, water dispersibility, and zeta potential were also determined. The hydrodynamic diameter of particles with silica and dye is 65.2 and 70.5 nm, respectively, with positive zeta potential (25.1, 38.5 mV). Furthermore magnetic properties of the particles were measured and the experimental results suggested that it could meet the requirement of application as magnetic resonance imaging agent. Finally to verify the availability of the particles as fluorescent labeling, protein labeling experiment was performed using bovine serum albumin (BSA) protein and the results showed that the dual functional particle has higher affinity with BSA than TO molecule itself.
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folate conjugated chitosan grafted Thiazole Orange derivative with high targeting for early breast cancer cells diagnosis
Journal of Fluorescence, 2012Co-Authors: Xuening Fei, Yin LiuAbstract:The folate receptor (FR) is over-expressed on many solid tumors and has been exploited for targeted delivery of folic acid linked liposomes to cancer cells in vitro. In the present study, we developed a novel folic acid (FA) conjugated chitosan (CTS) grafted Thiazole Orange (TO) complex (FA-CTS-TO), and the formation can be used to label tumor cells. The structure of TO derivatives was confirmed by 1H NMR and MS, and the fluorescence probe of FA-CTS-TO complex was confirmed by Fourier transform infrared analysis and Differential thermal analysis. The in vitro and in vivo of FA-CTS-TO complex were tested in breast cancer cells and the results showed a high targeting specificity in tumor cells with FR over-expressed. Such prominent fluorescence properties demonstrate again that FA-CTS-TO complex as a tumor targeting fluorescence probe is appropriate for breast cancer cells.
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fluorescent properties of novel dendrimer dyes based on Thiazole Orange
Journal of Luminescence, 2011Co-Authors: Xuening Fei, Yunquan Lan, Bin ShiAbstract:Abstract In this paper, polyamidoamine (PAMAM) dendrimers with active amino group of some generations (G=0.5–2) were prepared from commercial aminoacetaldehyde diethyl acetal by the divergent method. After that, Thiazole Orange (TO) with –COOH was incorporated with dendrimers of G=1 and 2 to afford novel dendrimer-TO dyes. The fluorescent properties studies showed that the fluorescent intensity of the same concentration of dendrimer-TO (G=2) was higher than that of the dendrimer-TO (G=1), and both of them were much stronger than free TO with –COOH. There was a fluorescent enhancement of the dendrimer dyes compared with free dye. The dendrimer dyes were of well-defined chemical structure,with little aggregation and self-quenching as well as good fluorescence properties of good stability, high intensity and sensitivity, which could be used in labeling cancer cells and further in diagnosis and detection of early-stage tumors.
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synthesis and crystal structure of Thiazole Orange derivative
Journal of Chemical Crystallography, 2011Co-Authors: Xuening Fei, Yunquan Lan, Bin Shi, Baolian ZhangAbstract:The title compound of Thiazole Orange derivative was synthesized by the reaction of benzothiazolium and 4-methyl quinoline salts, which was determined by 1HNMR and MS. A crystalline hydrate of Thiazole Orange derivative was obtained when the crystal formed and characterized by single-crystal X-ray diffraction. The crystal belongs to the Triclinic system, and the cell parameters of space group P-1 were a = 10.162(2) A, b = 10.501(2) A, c = 11.040(2) A, α = 92.17(3)o, β = 117.10(3)o, γ = 92.28(3)o, V = 1045.9(4) A3, Z = 2, Dc = 1.380 mg/m−3, μ = 0.2 mm−1, F(000) = 460, and the final R = 0.0625 and wR = 0.1862 for 3658 observed reflections (I > 2σ(I)). The two aromatic rings linked by the methylene bridged chain are a coplanar structure. The title compound of Thiazole Orange derivative with crystal water was synthesized and characterized by 1HNMR, MS, and single-crystal X-ray diffraction .
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targeted Thiazole Orange derivative with folate synthesis fluorescence and in vivo fluorescence imaging
Molecules, 2010Co-Authors: Xuening Fei, Yiqi Wang, Qingyang Meng, Baolian ZhangAbstract:A Thiazole Orange conjugated with folate derivative was synthesized in two steps. Firstly, folate was coupled with 1-(3-aminopropyl)-4-methylquinolinium bromide to afford folate-methylquinolinium bromide, which then reacted with benzothiazolium to obtain the title folate-conjugated compound. The compound was evaluated by 1H-NMR MS, TG/DTA and fluorescence spectroscopic methods. The title compound could selectively target folate receptor expressing tumors according to the in vivo fluorescence imaging preliminarily performed on nude mice with breast tumors.
Kun Zhang - One of the best experts on this subject based on the ideXlab platform.
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a series of modified Thiazole Orange dye as the highly fluorescent g quadruplex dna binders the study of electronic effects of the substituent on 1 methylquinolinium moiety
Journal of Luminescence, 2019Co-Authors: Wei Long, Jin-qiang Hou, Wingleung Wong, Qiang Deng, Qi Guo, Kun ZhangAbstract:Abstract The molecular of scaffold of Thiazole Orange has a number of merits for being as a fluorescent dye with tailor-made structure advancement for many useful applications. Structural modification based on 1-methylquinolinium moiety of Thiazole Orange is able to induce critical effects on fluorescent signal discrimination ability towards certain secondary or tertiary DNA structures. The electronic effect of the substituent on both molecular signaling and binding preference were investigated in the present study. We systematically compared the structural influence on the fluorescence signaling and binding preference towards nucleic acids in vitro through the addition of a number of substituent groups including p-methylstrylyl, p-hydroxylstyryl, p-chlorostyryl, p-bromostyryl, p-fluorostyryl, and (p-fluorobenzyl)-1,3-butadien-1-yl. The dyes synthesized were investigated with 19 nucleic acids for their interaction kinetics and fluorescent signal response with fluorescence titration experiments. The experimental results indicate that both the electronic effect and the molecular size of the dyes show significant influence on achieving higher binding affinity and fluorescent signal discrimination for G-quadruplex DNA. In addition, the dye with the introduction of a p-fluorostyryl substituent exhibits excellent linear relationship of the enhanced signal with respect to the concentration of telo21 DNA in vitro. The limit of detection (LOD) obtained was found to be 9 nM, which is much better than other analogues under the same conditions.
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boosting the turn on fluorescent signaling ability of Thiazole Orange dyes the effectiveness of structural modification site and its unusual interaction behavior with nucleic acids
Dyes and Pigments, 2018Co-Authors: Wei Long, Jin-qiang Hou, Kun Zhang, Xuanhe Huang, Senyuan Cai, Leonard G Luyt, Wingleung Wong, Cheukfai ChowAbstract:Abstract New fluorescent dyes derivatized on a classical Thiazole Orange framework are able to show unexpectedly strong interaction signal and unusual binding selectivity with different structures of nucleic acid, particularly when bound with double-stranded DNA or G-quadruplex DNA. The present study reveals that these small binding ligands simply bearing an additional amino side group on its parent molecule of Thiazole Orange have almost no background fluorescence in solution. Conversely, they are able to produce an extremely strong yellow emission signal upon interaction with targeting nucleic acids in live cells. The induced fluorescence intensity was approximately 10–15 times stronger than that of Thiazole Orange. The dyes are therefore excellent fluorescent stains for bio-sensing and bio-imaging applications. It is particularly suitable for fluorescence microscopy experiments requiring very low working concentration (0.25 μM or less) targeting nucleic acids. This was demonstrated using pu27 G-quadruplex DNA, which has a low limit of detection (LOD = 3–4 nM) while Thiazole Orange was much higher (LOD = 48.7 nM) under the same conditions. In addition, it was found that structural modification on the quinolinium scaffold of Thiazole Orange was less effective than modification on the benzoThiazole moiety. The findings of the present study provide important information for structural advancement of small molecules based on the widely used Thiazole Orange skeleton, resulting in analogues that are able to achieve higher sensitivity and selectivity for targeting at a specific class of nucleic acids. Computational docking studies were also conducted to illustrate the interaction behaviors of the dyes with different DNA structures.
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molecular engineering of Thiazole Orange dye change of fluorescent signaling from universal to specific upon binding with nucleic acids in bioassay
ACS Chemical Biology, 2016Co-Authors: Qiang Deng, Jin-qiang Hou, Kun Zhang, Leonard G Luyt, Wingleung Wong, Zhengya Wang, Cheukfai ChowAbstract:The universal fluorescent staining property of Thiazole Orange (TO) dye was adapted in order to be specific for G-quadruplex DNA structures, through the introduction of a styrene-like substituent at the ortho-position of the TO scaffold. This extraordinary outcome was determined from experimental studies and further explored through molecular docking studies. The molecular docking studies help understand how such a small substituent leads to remarkable fluorescent signal discrimination between G-quadruplex DNA and other types of nucleic acids. The results reveal that the modified dyes bind to the G-quadruplex or duplex DNA in a similar fashion as TO, but exhibit either enhanced or quenched fluorescent signal, which is determined by the spatial length and orientation of the substituent and has never been known. The new fluorescent dye modified with a p-(dimethylamino)styryl substituent offers 10-fold more selectivity toward telomeric G-quadruplexes than double-stranded DNA substrates. In addition, native PAGE experiments, FRET, CD analysis, and live cell imaging were also studied and demonstrated the potential applications of this class of Thiazole-Orange-based fluorescent probes in bioassays and cell imaging.
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molecular engineering of Thiazole Orange dye change of fluorescent signaling from universal to specific upon binding with nucleic acids in bioassay
ACS Chemical Biology, 2016Co-Authors: Qiang Deng, Jin-qiang Hou, Kun Zhang, Leonard G Luyt, Wingleung Wong, Zhengya Wang, Cheukfai ChowAbstract:The universal fluorescent staining property of Thiazole Orange (TO) dye was adapted in order to be specific for G-quadruplex DNA structures, through the introduction of a styrene-like substituent at the ortho-position of the TO scaffold. This extraordinary outcome was determined from experimental studies and further explored through molecular docking studies. The molecular docking studies help understand how such a small substituent leads to remarkable fluorescent signal discrimination between G-quadruplex DNA and other types of nucleic acids. The results reveal that the modified dyes bind to the G-quadruplex or duplex DNA in a similar fashion as TO, but exhibit either enhanced or quenched fluorescent signal, which is determined by the spatial length and orientation of the substituent and has never been known. The new fluorescent dye modified with a p-(dimethylamino)styryl substituent offers 10-fold more selectivity toward telomeric G-quadruplexes than double-stranded DNA substrates. In addition, native P...
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a molecular fluorescent dye for specific staining and imaging of rna in live cells a novel ligand integration from classical Thiazole Orange and styryl compounds
Chemical Communications, 2015Co-Authors: Qiang Deng, Kun Zhang, Wingleung Wong, Zhengya Wang, Baohua Huang, Yanxiong Fang, Cheukfai ChowAbstract:A new RNA-selective fluorescent dye integrated with a Thiazole Orange and a p-(methylthio)styryl moiety shows better nucleolus RNA staining and imaging performance in live cells than the commercial stains. It also exhibits excellent photostability, cell tolerance, and counterstain compatibility with 4′,6-diamidino-2-phenylindole for specific RNA–DNA colocalization in bioassays.
Mikael Kubista - One of the best experts on this subject based on the ideXlab platform.
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light up probes Thiazole Orange conjugated peptide nucleic acid for detection of target nucleic acid in homogeneous solution
Analytical Biochemistry, 2000Co-Authors: Nicke Svanvik, Gunnar Westman, Dongyuan Wang, Mikael KubistaAbstract:Abstract We have constructed light-up probes for nucleic acid detection. The light-up probe is a peptide nucleic acid (PNA) oligonucleotide to which the asymmetric cyanine dye Thiazole Orange (TO) is tethered. It combines the excellent hybridization properties of PNA and the large fluorescence enhancement of TO upon binding to DNA. When the PNA hybridizes to target DNA, the dye binds and becomes fluorescent. Free probes have low fluorescence, which may increase almost 50-fold upon hybridization to complementary nucleic acid. This makes the light-up probes particularly suitable for homogeneous hybridization assays, where separation of the bound and free probe is not necessary. We find that the fluorescence enhancement upon hybridization varies among different probes, which is mainly due to variations in free probe fluorescence. For eight probes studied the fluorescence quantum yield at 25°C in the unbound state ranged from 0.0015 to 0.08 and seemed to depend mainly on the PNA sequence. The binding of the light-up probes to target DNA is highly sequence specific and a single mismatch in a 10-mer target sequence was readily identified.
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light up probes Thiazole Orange conjugated peptide nucleic acid for detection of target nucleic acid in homogeneous solution
Analytical Biochemistry, 2000Co-Authors: Nicke Svanvik, Gunnar Westman, Dongyuan Wang, Mikael KubistaAbstract:We have constructed light-up probes for nucleic acid detection. The light-up probe is a peptide nucleic acid (PNA) oligonucleotide to which the asymmetric cyanine dye Thiazole Orange (TO) is tethered. It combines the excellent hybridization properties of PNA and the large fluorescence enhancement of TO upon binding to DNA. When the PNA hybridizes to target DNA, the dye binds and becomes fluorescent. Free probes have low fluorescence, which may increase almost 50-fold upon hybridization to complementary nucleic acid. This makes the light-up probes particularly suitable for homogeneous hybridization assays, where separation of the bound and free probe is not necessary. We find that the fluorescence enhancement upon hybridization varies among different probes, which is mainly due to variations in free probe fluorescence. For eight probes studied the fluorescence quantum yield at 25 degrees C in the unbound state ranged from 0.0015 to 0.08 and seemed to depend mainly on the PNA sequence. The binding of the light-up probes to target DNA is highly sequence specific and a single mismatch in a 10-mer target sequence was readily identified.
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the interactions between the fluorescent dye Thiazole Orange and dna
Biopolymers, 1998Co-Authors: Jan Nygren, Nicke Svanvik, Mikael KubistaAbstract:The interaction of the fluorescent dye Thiazole Orange (TO) with nucleic acids is characterized. It is found that TO binds with highest affinity to double-stranded (ds) DNA [log(K) ≈ 5.5 at 100 mM salt], about 5–10 times weaker to single-stranded polypurines, and further 10–1000 times weaker to single-stranded polypyrimidines. TO binds as a monomer to dsDNAs and poly(dA), both as a monomer and as a dimer to poly(dG) and mainly as a dimer to poly(dC) and poly(dT). The fluorescence quantum yield of TO free in solution is about 2 · 10−4, and it increases to about 0.1 when bound to dsDNA or to poly(dA), and to about 0.4 when bound to poly(dG). Estimated quantum yields of TO bound to poly(dC) and poly(dT) are about 0.06 and 0.01, respectively. The quantum yield of bound TO depends on temperature and decreases about threefold between 5 and 50°C. © 1998 John Wiley & Sons, Inc. Biopoly 46: 39–51, 1998
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the interactions between the fluorescent dye Thiazole Orange and dna
Biopolymers, 1998Co-Authors: Jan Nygren, Nicke Svanvik, Mikael KubistaAbstract:The interaction of the fluorescent dye Thiazole Orange (TO) with nucleic acids is characterized. It is found that TO binds with highest affinity to double-stranded (ds) DNA [log (K) approximately 5.5 at 100 mM salt], about 5-10 times weaker to single-stranded polypurines, and further 10-1000 times weaker to single-stranded polypyrimidines. TO binds as a monomer to dsDNAs and poly(dA), both as a monomer and as a dimer to poly(dG) and mainly as a dimer to poly(dC) and poly(dT). The fluorescence quantum yield of TO free in solution is about 2 x 10(-4), and it increases to about 0.1 when bound to dsDNA or to poly(dA), and to about 0.4 when bound to poly(dG). Estimated quantum yields of TO bound to poly(dC) and poly(dT) are about 0.06 and 0.01, respectively. The quantum yield of bound TO depends on temperature and decreases about threefold between 5 and 50 degrees C.