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Highly Sensitive Detection (highly + sensitive_detection)

Distribution by Scientific Domains

Life Sciences	50%

Selected Abstracts

Highly sensitive detection of the MGB1 transcript (mammaglobin) in the peripheral blood of breast cancer patients

INTERNATIONAL JOURNAL OF CANCER, Issue 4 2004
Nuno Cerveira
Abstract We describe a new one-step RT-PCR assay for the detection of the mammaglobin (MGB1) gene transcript in the peripheral blood of breast cancer patients. With this approach, the MGB1 transcript could be detected in the peripheral blood of 22 of 54 (41%) breast cancer patients prior to any therapy. This method, using specific primers for cDNA synthesis, proved to be more sensitive (10,6 to 10,11, usually 10,7) than previously reported methodologies. This increased sensitivity was achieved without compromising specificity, as the MGB1 transcript was not detected in 38 blood samples of healthy donors and in only 1 of 18 blood samples of patients presenting with hematologic malignancies. A positive correlation was seen between MGB1 positivity and breast cancer stage: 0/3 (0%) in stage 0, 3/13 (23%) in stage I, 6/17 (35%) in stage II, 5/10 (50%) in stage III, 8/11 (73%) in stage IV (p = 0.003). The prognostic and therapeutic implications of MGB1 positivity by one-step RT-PCR in the peripheral blood of breast cancer patients, especially in clinically localized disease (stages I and II), should be evaluated after long-term clinical follow-up of these patients. © 2003 Wiley-Liss, Inc. [source]

Optimization of the electrokinetic supercharging preconcentration for high-sensitivity microchip gel electrophoresis on a cross-geometry microchip

ELECTROPHORESIS, Issue 14 2004
Zhongqi Xu
Abstract We developed a novel on-line preconcentration procedure for microchip gel electrophoresis (MCGE), which enables application of electrokinetic supercharging (EKS) for highly sensitive detection of DNA fragments on a cross-geometry microchip. In comparison with conventional pinched injection using the cross microchip, the present approach allows loading a much larger amount of the sample by taking advantage of a newly developed operational mode. In order to obtain high preconcentration effect and prevent splitting of an enriched sample into subchannels, i.e., off the detector range, effects of the voltage applied on the reservoirs and the time of isotachophoretic preconcentration were examined. The optimal balance between the voltage and time was found for a high-sensitivity analysis of DNA fragments. After experimental optimization the detection limit of a 150 bp fragment was as low as 0.22 mg/L (S/N = 3) that is 10 times better than using the conventional pinched injection. [source]

Highly Surface-roughened "Flower-like" Silver Nanoparticles for Extremely Sensitive Substrates of Surface-enhanced Raman Scattering

ADVANCED MATERIALS, Issue 45 2009
Hongyan Liang
Abstract Surface-enhanced Raman scattering (SERS) is a new optical spectroscopic analysis technique with potential for highly sensitive detection of molecules. Recently, many efforts have been made to find SERS substrates with high sensitivity and reproducibility. In this Research News article, we provide a focused review on the synthesis of monodispersed silver particles with a novel, highly roughened, "flower-like" morphology by reducing silver nitrate with ascorbic acid in aqueous solutions. The nanometer-scale surface roughness of the particles can provide several hot spots on a single particle, which significantly increases SERS enhancement. The incident polarization-dependent SERS of individual particles is also studied. Although the different "hot spots" on a single particle can have a strong polarization dependency, the total Raman signals from an individual particle usually have no obvious polarization dependency. Moreover, these flower-like silver particles can be measured by SERS with high enhancement several times, which indicates the high stability of the hot spots. Hence, the flower-like silver particles here can serve as highly sensitive and reproducible SERS substrates. [source]

Development of a strategy for transgenic studies and monitoring of transgene expression in two closely related Moricandia species possessing a C3 or C3,C4 intermediate photosynthetic phenotype

PHYSIOLOGIA PLANTARUM, Issue 1 2003
Vera Thole
In order to establish a model system for comparative studies of C3 and C3,C4 intermediate photosynthesis, the development of efficient transformation systems and the monitoring of transgene behaviour and stability were carried out in two closely related Moricandia species (Brassicaceae): the C3,C4 photosynthetic intermediate species M. arvensis and the C3 species M. moricandioides. In this study the green fluorescent protein (gfp) reporter gene was used as a vital marker gene while the use of the , -glucuronidase (gusA) gene was based on the highly sensitive detection of its activity. For Agrobacterium -mediated transformation of leaf explants, a cauliflower mosaic virus 35S promoter-driven, modified version of gfp, the mgfp5-ER gene and the gusA gene, respectively, were introduced into the new dual binary transformation vector system pGreen/pSoup (Hellens et al. 2000, Plant Mol Bio 42: 819,832). GFP5 produced bright-green fluorescence in transformed tissues that was distinctly detected 5,12 days following transformation in developing calli of the two species. Visual screening, combined with antibiotic selection, enabled early and easy identification of transformation events and contributed to improvements in the transformation strategies. Transgene integration studies demonstrated that mgfp5-ER was inserted with low copy number in the M. arvensis plant lines and the transgene was transmitted in a Mendelian fashion to T1 and T2 progenies. GFP5 expression levels in a population of 100 independent primary transformed M. arvensis plant lines (T0) showed great variation between transformation events (coefficient of variation of 108%). The mgfp5-ER or gusA reporter genes were expressed in 90,95% of the kanamycin-resistant M. arvensis plant lines and in up to 98% of the independent M. moricandioides plant lines. [source]