4,723 research outputs found
Fluorescence based strategies for genetic analysis
No full textSynthetic chemistry has been central to the design of modern methods of genetic analysis. In this article, we discuss the underlying chemistry and biophysical principles that have been used in the development of robust methods for the analysis of DNA in the diagnostic laboratory
Ultrasensitive fluorescence-based methods for nucleic acid detection: towards amplification-free genetic analysis
Get PDFReal time PCR is the mainstay of current nucleic acid assays, underpinning applications in forensic science, point-of-care diagnostics and detection of bioterrorism agents. Despite its broad utility, the search for new tests continues, inspired by second and third generation DNA sequencing technologies and fuelled by progress in single molecule fluorescence spectroscopy, nanotechnology and microfabrication. These new methods promise the direct detection of nucleic acids without the need for enzymatic amplification. In this feature article, we provide a chemist's perspective on this multidisciplinary area, introducing the concepts of single molecule detection then focussing on the selection of labels and probe chemistry suitable for generating a signal detectable by ultrasensitive fluorescence spectroscopy. Finally, we discuss the further developments that are required to incorporate these detection platforms into integrated ‘sample-in-answer-out’ instruments, capable of detecting many target sequences in a matter of minute
Linear fluorescent oligonucleotide probes with an acridine quencher generate a signal upon hybridisation
No full textLinear, single stranded probes incorporating a fluorophore and an acridine moiety are weakly fluorescent until hybridised to a complementary target nucleic acid whereupon fluorescence increases due to reduced quenching
Radioactive reverse transcription PCR (RT-PCR) analysis of strain SSB318 complemented with wt or C238/C239
No full text<p><b>Copyright information:</b></p><p>Taken from " and investigation of bacterial type B RNase P interaction with tRNA 3′-CCA"</p><p></p><p>Nucleic Acids Research 2007;35(6):2060-2073.</p><p>Published online 13 Mar 2007</p><p>PMCID:PMC1874595.</p><p>© 2007 The Author(s)</p> PCR products were analyzed on a 10% polyacrylamide/8 M urea gel. Lanes 1–30: total RNA from SSB318 complemented with wt (lanes 1–4 and 13-16), C238 (lanes 5–8, 17–20 and 25–30) or C239 (lanes 9–12 and 21–24) grown at 37°C in the absence of IPTG and in the presence of 2% xylose (w/v); amounts of total RNA were 200 ng in lanes 1–24, 26 and 29, 100 ng in lanes 25 and 28, and 400 ng in lanes 27 and 30. P : presence (+) or absence (−) of a xylose-inducible plasmid-encoded gene. Lanes 1–12 and 25–27: primers specific for ; lanes 13–24 and 28–30: primers specific for the mRNA encoding ribosomal protein S18 (S18). AMV: presence (+) or absence (−) of reverse transcriptase. For details on RT-PCR, see the Material and Methods section. Lanes 25–30 document that the amount of RT-PCR product was sensitive to RNA template concentration. The figure illustrates a representative experiment, but the results shown here were reproduced in five individual experiments using three independent total RNA preparations
Prescribing by mental health nurses: the UK perspective
No full textPURPOSE. This article aims to discuss the growth of mental health nurse (MHN) prescribing in the United Kingdom as an exemplar for readers to compare progress in their own countries and context. This study also aims to provide a historical overview of this process in the United Kingdom where MHNs prescribe safely and competently.
CONCLUSIONS. Finally, evidence has shown that MHNs with prescriptive authority are competent when prescribing when compared to psychiatrists.
PRACTICE IMPLICATIONS. Despite organizational barriers and educational concerns, MHN prescribing is becoming embedded in the healthcare context in the United Kingdo
Modular RT-Motion USB Software Framework
No full textPhilips Applied Technologies has developed the RT-Motion USB platform as a compact distributed real-time motion control platform, but the platform can still be improved by developing a more advanced software framework. The goal of this thesis project is to design a modular software framework to complement the RT-Motion USB platform with extendability, flexibility, and configurability. The design focuses on the extendability of the platform by developing foundation building blocks to integrate software extension modules and device drivers easily. The design emphasizes the principle of simplicity to ensure the lowest possible overhead and highest reliability. The firmware is modular, which allows each module to concentrate on its own area. The implementation of the design has been tested and is proved to provide extendability, flexibility, and configurability while incurring low overhead. The improvement to the RT-Motion USB platform is expected to extend the applicability of the RT-Motion USB platform to a broader application range.Microelectronics & Computer EngineeringElectrical Engineering, Mathematics and Computer Scienc
Naphthalenyl- and anthracenyl-ethynyl dT analogues as base discriminating fluorescent nucleosides and intramolecular energy transfer donors in oligonucleotide probes
No full textFluorescent thymidine analogues functionalised in the 5-position with the moieties naphthalenylethynyl (NeT), anthracenylethynyl (AeT) and anthracenylbuta-1,3-diynyl (AeeT) have been incorporated into oligonucleotides. The modified oligonucleotides undergo significant emission enhancement when hybridised to fully complementary strands and a decrease in fluorescence emission when the modified thymine is paired with guanine. Thus these analogues are potentially useful as base discriminating fluorescent nucleosides (BDFs). When a fluorescein dT monomer is incorporated into the same oligonucleotide strand as the modified base, energy transfer enhances the fluorescein emission, particularly upon duplex formation. These dual-labelled probes may be useful for genetic analysis to detect point mutations and SNPs and could provide multiplexing capability
A real-time PCR assay to estimate Leishmania chagasi load in its natural sand fly vector Lutzomyia longipalpis
Get PDFLeishmania chagasi, transmitted mainly by Lutzomyia longipalpis sand flies, causes visceral leishmaniasis and atypical cutaneous leishmaniasis in Latin America. Successful vector control depends upon determining vectorial capacity and understanding Leishmania transmission by sand flies. As microscopic detection of Leishmania in dissected sand fly guts is laborious and time-consuming, highly specific, sensitive, rapid and robust Leishmania PCR assays have attracted epidemiologists' attention. Real-time PCR is faster than qualitative PCR and yields quantitative data amenable to statistical analyses. A highly reproducible Leishmania DNA polymerase gene-based TaqMan real-time PCR assay was adapted to quantify Leishmania in sand flies, showing intra-assay and inter-assay coefficient variations lower than 1 and 1.7%, respectively, and sensitivity to 10 pg Leishmania DNA ( approximately 120 parasites) in as much as 100 ng sand fly DNA. Data obtained for experimentally infected sand flies yielded parasite loads within the range of counts obtained by microscopy for the same sand fly cohort or that were around five times higher than microscopy counts, depending on the method used for data analysis. These results highlight the potential of quantitative PCR for Leishmania transmission studies, and the need to understand factors affecting its sensitivity and specificity
Exploring the effects od a rigid body on the evolution of the Rayleigh-Taylor instability
No full textThis talk discusses the effects of a rigid solid boundary impeding the evolution of the Rayleigh-Taylor (RT) instability. The introduction of an obstacle completely alters the evolution of RT growth, instead of mixing the domain rapidly, a quasi-steady flow, rich in dynamics is established for long periods of time. Using a combination of low Atwood number experiments and ILES simulations, this talk will present a non-dimensional analytical model for a multi-stage mixing process, discussing the effects of the opening size and topology on the density change of each layer, buoyancy driven flux through the opening and mixing efficiency
Recognition of CG inversions in DNA triple helices by methylated 3H-pyrrolo [2,3-d] pyrimidin-2(7H)-one nucleoside analogues
No full textSubstituted 3H-pyrrolo[2,3-d] pyrimidin-2(7H)-one nucleoside analogues have been synthesised from 5-alkynyl-uridine derivatives, incorporated into triplex forming oligonucleotides (TFOs) and found to selectively bind CG inversions with enhanced affinity compared to T
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