1,721,148 research outputs found
Transgenes monitoring in an industrial soybean processing chain by DNA-based conventional approaches and biosensors
No full textDetection of fragmented genomic DNA by PCR-free piezoelectric sensing using a denaturation approach
No full textDevelopment of well-automated and miniaturized gene analysis methods is the objective at which research is currently aiming. Recent works report examples of miniaturized PCR devices1 pointing at high-speed PCR. However, a great improvement in DNA sequence analysis would come by direct detection in nonamplified genomic DNA. Biosensors represent an interesting candidate for DNA detection. In particular, several DNA-based sensors have been reported. Most of the work was applied to PCR-amplified samples, and only few works, operating directly with genomic DNA, appeared in the literature with different detection principles.
In this paper, a piezoelectric sensor for direct detection of sequences in nonamplified genomic DNA is reported.
The system relies on realtime and label-free detection of the hybridization reaction between an immobilized probe (25-mer) and the complementary sequence in solution. The DNA probe is immobilized on the gold electrodes of 10 MHz quartz crystals. Genomic DNA was extracted from the plant, Nicotiana glauca, used as a model system. The target sequence was a portion of the
promoter region (35S, present in various genetically modified organisms (GMOs), used as a marker for GMO screening
Gene Delivery Markers For Gene Doping Detection: A Model Study by Affinity-Based Biosensors
No full text
Combination of amplification and post-amplification strategies to improve optical DNA sensing
No full textApproaches to optimise detection of polymerase chain reaction (PCR) amplified DNA samples by an optical sensor based on surface plasmon resonance (SPR) (BiacoreX(TM
DEVELOPMENT OF PIEZOELECTRIC- AND SPR IMAGING-BASED BIOSENSORS FOR GENE DOPING DETECTION
No full textComparative determination of some phytohormones in wild-type and genetically modified plants by gas chromatography–mass spectrometry and high-performance liquid chromatography–tandem mass spectrometry
No full textThe analytical performances of two optimized analytical methodologies used for the determination of
auxins, cytokinins, and abscisic acid in plant samples were critically compared. Phytohormones were
extracted from Nicotiana glauca samples using a modified Bieleski solvent and determined both by gas
chromatography–mass spectrometry (GC–MS), after derivatization with N,O-bis(trimethylsilyl)trifluoroacetamide
(BSTFA), and by high-performance liquid chromatography–tandem mass spectrometry (HPLC–
MS/MS) on the Bieleski extract without any further treatment. HPLC–MS/MS gave better results in terms
of higher coefficients of determination of the calibration curves, higher and more reproducible recoveries,
lower limits of detection, faster sample preparation, and higher sample throughput. Thus, two sets of N.
glauca and N. langsdorffii samples, both wild-type and genetically modified by inserting the glucocorticoid
receptor (GR) gene encoding for the rat glucocorticoid receptor, were first characterized by reverse transcriptase-
polymerase chain reaction (RT-PCR) analysis and then analyzed by HPLC–MS/MS. Significant differences
in the phytohormone content between the two sample sets were found and are very important
in terms of understanding the mechanisms and effects on growth processes and the development of
transgenic plants
Transgenes monitoring in an industrial soybean processing chain by DNA-based conventional approaches and biosensors
No full textThe development of analytical methods for genetically modified organisms (GMO) screening is of great interest. In particular, since even highly processed GMO-derived food products are covered by new European legislations, a great effort has been devoted to the application of the analytical tests to these products. This work describes a polymerase chain reaction-based qualitative screening assay and a biosensor based approach to detect transgenes in a Roundup Ready_ soybean processing line. Roundup Ready_ soybean was specifically analyzed in eight types of processed materials – seeds, crushed seeds, expander, crude flour, proteic flour, crude oil, degummed oil and lecithin – all derived from the same initial source and produced during the manufacturing process. Specific combinations of primers were used to differentiate sequences from the whole insert. The amplification of ‘‘marker” fragments with a maximum length of 500 bp was successfully achieved both in raw material (seeds) and in partially (crushed seeds, crude and proteic flours) and highly (crude and degummed oils and fluid lecithin) processed materials. Moreover, the extraction procedure was optimised and the polymerase chain reaction-electrophoresis analysis has been implemented by a biosensor-based approac
The rat glucocorticoid receptor integration in Nicotiana langsdorffii genome affects plant responses to abiotic stresses and to arbuscular mycorrhizal symbiosis
Full text linkThe present study reports evidence of the pleiotropic effects caused by the insertion of the rat glucocorticoid receptor (GR) into the genome of Nicotiana langsdorffii. Transgenic N. langsdorffii-GR plants and the wild-type genotypes were analysed for their phenotypic and physiological characteristics. The integration of the GR gene affected flowering, growth habit, leaf morphology and stomatal pattern. Furthermore, GR plants showed an increased tolerance to heavy metal, drought and heat stress as evidenced by electrolyte leakage and by cell dedifferentiation and differentiation capability after recovery from stress treatments. We also monitored the establishment of the beneficial symbiosis between transgenic plants and the mycorrhizal fungus Funneliformis mosseae whose presymbiotic growth was significantly reduced by root exudates of N. langsdorffii-GR plants. The observed pleiotropic responses of transgenic plants may be a consequence of the hormonal imbalance, putatively due to the interaction of the GR receptor with the host genetic background. Our findings suggest that N. langsdorffii-GR plants can be used as a functional model system for the study of plant responses to a series of environmental stimuli
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