Rapid separation and laser-induced fluorescence detection of mutated DNA by capillary electrophoresis in a self-coating, low-viscosity polymer matrix

The detection of point and other simple mutations in DNA is important for cancer research and diagnosis and other biological studies. Capillary electrophoresis has been successfully used for separating DNA fragments. However, a low-viscosity polymer sieving buffer for DNA separation with on-line coating has never been reported. In this paper, a new method using capillary electrophoresis with on-line coating and laser-induced fluorescence detection (CE-LIF) for screening for point or simple DNA mutations has been demonstrated. The method uses an on-line dynamic coating technique that increases capillary lifetime and analysis reproducibility, and employs a low-viscosity polymer solution, which allows the user to rinse the capillary rapidly and refill with polymer solution easily. Experiments proved that the additives in the separation buffer for on-line capillary coating do not affect the separation efficiency of the running buffer, and do not interfere with the formation of hydrogen-bonded network between boric acid, mannitol and hydroxypropylmethylcellulose polymers. The stability of the dynamically coated capillary was quantitatively studied; the capillary lifetime was increased 6- to 7-fold compared with that of permanently coated CE columns. Standard DNA fragments containing mutations, with sizes of 209, 219, and 338 bps, were successfully separated and detected with this system, after the mutated DNA fragments were cleaved by CEL-I endonuclease. The technique is very sensitive for the size-separation of low-range, middle-range, and high-range DNA fragments. Results were compared with the HPLC methods developed by Transgenomic, Inc. and were in good agreement. The method should be applicable to mutation detection for all relevant biological and clinical studies. The factors influencing separations and the stability of dynamic capillary coatings are also discussed in the paper.     

Single-sweep polarography of the copper(II)-3-hydroxy-1-p-sulphonatophenyl-3-phenyltriazene complex and its analytical applications

A polarographic investigation of the copper-3-hydroxy-1-p-sulphonatophenyl-3-phenyltriazene (HSPT) complex in 0.05 M sodium tetraborate medium is described and a simple and sensitive single-sweep polarographic method for the determination of trace amounts of copper in biological samples is proposed. The complex was shown to be Cu(HSPT)2 with log beta' = 11.38. The polarographic wave is caused by the reduction of copper(II) in the adsorbed complex to copper amalgam on the surface of a mercury electrode. The current peak is directly proportional to the concentration of copper in the range 8.0 x 10(-9)-4.0 x 10(-6) M and the detection limit is 5.0 x 10(-9) M.     

Microanalysis of nitro compounds. II

Summary A colorimetric method for the determination of phenolic compounds containing the nitro function is described. It is based on the production of a yellow color when nitrophenols are treated with iminobispropylamine in monochlorobenzene solution. There is no interference due to the presence of carbonyl and carboxyl groups in the molecule. Relationship between absorbance and concentration is linear in the range of 1 to 20g/ml for most nitrophenols. Isomeric compounds can be distinguished by the absorption spectra of their respective colored complexes.

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Zusammenfassung Ein kolorimetrisches Verfahren zur Bestimmung phenolischer Nitroverbindungen wurde beschrieben. Es beruht auf der gelben Farbreaktion der Nitrophenole mit Imino-bis-propylamin in monochlorbenzolischer Lösung. Carbonyl-und Carboxylgruppen stören nicht. Absorption und Konzentration verhalten sieh bei den meisten Nitrophenolen zwischen 1 und 20g/ml linear. Isomere Verbindungen können an dem Absorptionsspektrum ihrer gefärbten Komplexverbindungen unterschieden werden.

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Résumé On décrit une méthode colorimétrique pour le dosage des composés phénoliques contenant la fonction nitro. Elle est fondée sur la formation d'une coloration jaune quand les nitrophénols sont traités par l'imino-bispropylamine en solution dans le monochlorobenzene. Il n'y a pas d'interférence due à la présence de groupes carbonyles et carboxyles dans la molécule. La relation entre la densité optique et la concentration est linéaire dans le domaine de 1 à 20g/ml pour la plupart des nitrophénols. On peut distinguer les composés isomères par les spectres d'absorption de leurs complexes colorés respectifs.

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For Part I of this series, see ref. 7.     

Synthesis of giant rigid pi-conjugated dendrimers

A novel family of giant pi-conjugated dendrimers (G0, G1, and G2) solely constructed by 5,5,10,10,15,15-hexahexyltruxene units has been developed in a convergent manner through a Suzuki cross-coupling reaction. The overall yields to such large rigid conjugated dendrimers are quite satisfying. The structures and purity of these nanosize rigid dendrimers are verified by 1H and 13C NMR, MALDI-TOF MS, and elemental analysis.     

A Luminescent Cage‐Like Complex Constructed by Bidentate Pyridine‐Containing Ligand and Silver Nitrate

The cage‐like complex, Ag₄L₄(NO₃)₄ ( 1 ) [L = 1, 4‐bis(pyridine‐2‐ylmethoxy)benzene] was synthesized by the reaction of the flexible bidentate ligand and silver nitrate. It was characterized by elemental analysis, IR spectroscopy, TG, and single‐crystal X‐ray analysis. Complex 1 is reported as the first cage‐like cluster constructed by four nitrate anions bridging two [2+2] macrocycles. A blue luminescent emission and luminescent enhancement effect are observed in complex 1 .     

Synthesis of bicyclic pyrimidine derivatives as ATP analogues

A highly efficient and general solid-phase synthesis of bicyclic pyrimidine derivatives that target purine dependent proteins is reported. The synthesis of the key intermediate, 4,6-disubstituted-5-amino-pyrimidine, involved reduction of the corresponding nitro derivatives using 1,1'-dioctyl-viologen in a triphasic milieu. The mild reduction conditions enable the use of any acid labile solid support as well as a wide range of combinatorial substituents, thus enabling the synthesis of large libraries of highly diverse bicyclic pyrimidines. Alternative reduction conditions with tin(II) chloride and structure-reactivity studies are discussed as well.     

Effect of Calix[4]pyrrole as Addition Reagent on Anions Separation in Capillary Zone Electrophoresis (CZE)

Calixpyrroles, as new macrocyclic receptors, have gain increasing interest in host-guest chemistry. Pioneering work in this area by Sessler and co-workers have evidenced that calix[4]pyrroles are effective anion binding agents and have used for anion binding, sensing and new anion separation technologies1, 2. In this letter, we report that calix[4]pyrroles A, B and C3,4 (Scheme 1) can serve as additives in CZE for the separa- tion of halide ions. Scheme 1 A B C When analyzing anions with…     

Determination of Kinetic Parameters of Phase Transition on the Basis of DTA Measurements

A simple method of determination of kinetic parameters by analysis of DTA(t) function was developed for the case of systems undergoing transitions without mass change and when kinetic equation describing transition rate is known. The presented method also permits the determination of transition rate dα/dt (or α(t )) when the kinetic equation of transition is unknown. The developed method was tested using DTA data of crystallization of 2CaO×Al₂ O₃ ×1.95SiO₂ glass pure and doped with Cr³⁺ and Nd³⁺ . This revised version was published online in July 2006 with corrections to the Cover Date.