lab-on-a-chip Dotaz Zobrazit nápovědu
sv.
- MeSH
- mikrofluidní analytické techniky MeSH
- Publikační typ
- periodika MeSH
- Konspekt
- Chemie. Mineralogické vědy
- NLK Obory
- chemie, klinická chemie
- fyzika, biofyzika
- biologie
The global risk of viral disease outbreaks emphasizes the need for rapid, accurate, and sensitive detection techniques to speed up diagnostics allowing early intervention. An emerging field of microfluidics also known as the lab-on-a-chip (LOC) or micro total analysis system includes a wide range of diagnostic devices. This review briefly covers both conventional and microfluidics-based techniques for rapid viral detection. We first describe conventional detection methods such as cell culturing, immunofluorescence or enzyme-linked immunosorbent assay (ELISA), or reverse transcription polymerase chain reaction (RT-PCR). These methods often have limited speed, sensitivity, or specificity and are performed with typically bulky equipment. Here, we discuss some of the LOC technologies that can overcome these demerits, highlighting the latest advances in LOC devices for viral disease diagnosis. We also discuss the fabrication of LOC systems to produce devices for performing either individual steps or virus detection in samples with the sample to answer method. The complete system consists of sample preparation, and ELISA and RT-PCR for viral-antibody and nucleic acid detection, respectively. Finally, we formulate our opinions on these areas for the future development of LOC systems for viral diagnostics.
- MeSH
- biosenzitivní techniky MeSH
- design vybavení MeSH
- DNA virů analýza MeSH
- ELISA MeSH
- kvantitativní polymerázová řetězová reakce MeSH
- laboratoř na čipu * MeSH
- lidé MeSH
- mikrofluidní analytické techniky přístrojové vybavení MeSH
- nukleové kyseliny analýza MeSH
- virové nemoci diagnóza MeSH
- vyšetření u lůžka MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
INTRODUCTION: Nowadays, on-a-chip capillary electrophoresis is a routine method for the detection of PCR fragments. The Agilent 2100 Bioanalyzer was one of the first commercial devices in this field. Our project was designed to study the characteristics of Agilent DNA 1000 kit in PCR fragment analysis as a part of circulating tumour cell (CTC) detection technique. Despite the common use of this kit a complex analysis of the results from a long-term project is still missing. MATERIALS AND METHODS: A commercially available Agilent DNA 1000 kit was used as a final step in the CTC detection (AdnaTest) for the determination of the presence of PCR fragments generated by Multiplex PCR. Data from 30 prostate cancer patients obtained during two years of research were analyzed to determine the trueness and precision of the PCR fragment size determination. Additional experiments were performed to demonstrate the precision (repeatability, reproducibility) and robustness of PCR fragment concentration determination. RESULTS: The trueness and precision of the size determination was below 3% and 2% respectively. The repeatability of the concentration determination was below 15%. The difference in concentration determination increases when Multiplex-PCR/storage step is added between the two measurements of one sample. CONCLUSIONS: The characteristics established in our study are in concordance with the manufacturer's specifications established for a ladder as a sample. However, the concentration determination may vary depending on chip preparation, sample storage and concentration. The 15% variation of concentration determination repeatability was shown to be partly proportional and can be suppressed by proper normalization.
- MeSH
- aktiny genetika MeSH
- antigeny povrchové genetika MeSH
- DNA nádorová genetika MeSH
- erbB receptory genetika MeSH
- glutamátkarboxypeptidasa II genetika MeSH
- laboratoř na čipu * MeSH
- lidé MeSH
- multiplexová polymerázová řetězová reakce metody MeSH
- nádorové biomarkery genetika MeSH
- nádorové cirkulující buňky metabolismus MeSH
- nádory prostaty rezistentní na kastraci krev genetika MeSH
- prostatický specifický antigen genetika MeSH
- reagenční diagnostické soupravy MeSH
- regulace genové exprese u nádorů * MeSH
- reprodukovatelnost výsledků MeSH
- Check Tag
- lidé MeSH
- mužské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
The development of integrated, fast and affordable platforms for pathogen detection is an emerging area where a multidisciplinary approach is necessary for designing microsystems employing miniaturized devices; these new technologies promise a significant advancement of the current state of analytical testing leading to improved healthcare. In this work, the development of a lab-on-chip microsystem platform for the genetic analysis of Salmonella in milk samples is presented. The heart of the platform is an acoustic detection biochip, integrated with a microfluidic module. This detection platform is combined with a micro-processor, which, alongside with magnetic beads technology and a DNA micro-amplification module, are responsible for performing sample pre-treatment, bacteria lysis, nucleic acid purification and amplification. Automated, multiscale manipulation of fluids in complex microchannel networks is combined with novel sensing principles developed by some of the partners. This system is expected to have a significant impact in food-pathogen detection by providing for the first time an integrated detection test for Salmonella screening in a very short time. Finally, thanks to the low cost and compact technologies involved, the proposed set-up is expected to provide a competitive analytical platform for direct application in field settings.
- MeSH
- DNA bakterií analýza MeSH
- laboratoř na čipu mikrobiologie MeSH
- mléko mikrobiologie MeSH
- potravinářská mikrobiologie metody MeSH
- Salmonella genetika izolace a purifikace MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Acute intoxication incidents due to neurotoxic organophosphate (OP) insecticides are occasionally reported, related either to suicidal attempts or occupational exposure due to the misuse of protective equipment. Among them, chlorpyrifos is a compound related to great controversy, which is still authorized and easily accessible in many countries around the world. However, to screen for its exposure markers, instrumental methods are commonly applied, which cannot enable rapid monitoring at an early stage of an intoxication. Therefore, in this study, a microfluidic paper-based analytical device (μPAD) able to rapidly screen for chlorpyrifos-oxon, the toxic chlorpyrifos metabolite, in human serum was developed and fully validated. The μPAD combines wax-printed butyrylcholinesterase (BChE) paper sensors, a lab-on-a-chip (LOC) prototype injector and a smartphone as the analytical detector. In principle, the wax-printed strips with adsorbed BChE are embedded into LOC injectors able to deliver samples and reagents on-demand. A smartphone reader was used to monitor the color development on the strips providing binary qualitative results. μPAD method performance characteristics were thoroughly evaluated in terms of specificity, detection capability (CCβ) and ruggedness. The developed analytical platform is rapid (results within 10 min), cost-efficient (0.70 €), potentially applicable at the point-of-need and attained a low CCβ (10 μg L-1 in human serum). Finally, μPAD characteristics were critically compared to well-established methods, namely an in-house BChE microplate assay and liquid chromatography tandem mass spectrometry.
- MeSH
- chytrý telefon MeSH
- dursban * MeSH
- laboratoř na čipu MeSH
- lidé MeSH
- mikrofluidika MeSH
- mikrofluidní analytické techniky * MeSH
- papír MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
There is a constant need for the development of easy-to-operate systems for the rapid and unambiguous identification of bacterial pathogens in drinking water without the requirement for time-consuming culture processes. In this study, we present a disposable and low-cost lab-on-a-chip device utilizing a nanoporous membrane, which connects two stacked perpendicular microfluidic channels. Whereas one of the channels supplies the sample, the second one attracts it by potential-driven forces. Surface-enhanced Raman spectrometry (SERS) is employed as a reliable detection method for bacteria identification. To gain the effect of surface enhancement, silver nanoparticles were added to the sample. The pores of the membrane act as a filter trapping the bodies of microorganisms as well as clusters of nanoparticles creating suitable conditions for sensitive SERS detection. Therein, we focused on the construction and characterization of the device performance. To demonstrate the functionality of the microfluidic chip, we analyzed common pathogens (Escherichia coli DH5α and Pseudomonas taiwanensis VLB120) from spiked tap water using the optimized experimental parameters. The obtained results confirmed our system to be promising for the construction of a disposable optical platform for reliable and rapid pathogen detection which couples their electrokinetic concentration on the integrated nanoporous membrane with SERS detection.
- MeSH
- design vybavení MeSH
- kovové nanočástice chemie MeSH
- laboratoř na čipu * MeSH
- mikrofluidní analytické techniky přístrojové vybavení MeSH
- pitná voda mikrobiologie MeSH
- Ramanova spektroskopie přístrojové vybavení MeSH
- stříbro chemie MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Currently, robots are mostly used in industry (production lines and machining centers), where allow high productivity and accuracy of work that human is not able to achieve. One of the many areas of operation of remote robotic systems are places for human risky or inaccessible. For this reason, there is a robotic device capable of analyzing samples in the location of their occurrence, and sending the obtanined data. Thanks to the development of these technologies environmental problems without risk to humans may be solved. The knowledge acquired from the application of these technologies can be further used in space research. In this review, we deal with microflow systems that are used for a wide range of applications, which are summarized in this work.
This review brings a survey of the literature on analytical isotachophoresis (ITP) from the years 2010-2012. It confirms the fact that ITP alone is not used for analyses frequently but that its online combinations with other methods are of paramount importance. This review shows that the inherent features of the technique and first of all its concentrating ability are still unique for reaching high sensitivity and efficient sample cleanup in analytical applications. The part devoted to theory is mostly represented by computer simulations and confirms the power and significance of this approach. The section oriented at instrumentation and techniques shows the advantages of ITP in column combinations and microchip techniques. The chapter reviewing the applications is categorized according to the techniques applied, viz., column switching, on line ITP-CZE and on-chip analyses. The final part of the review is devoted to the nearly omnipresent electrophoresis principle of transient isotachophoresis, and to the advantages that it may offer for detection and sampling. In all parts, the significance of the operational conditions is also considered and where possible, the electrolyte system is explicitly presented.
We propose a label-free biosensor concept based on the charge state manipulation of nitrogen-vacancy (NV) quantum color centers in diamond, combined with an electrochemical microfluidic flow cell sensor, constructed on boron-doped diamond. This device can be set at a defined electrochemical potential, locking onto the particular chemical reaction, whilst the NV center provides the sensing function. The NV charge state occupation is initially prepared by applying a bias voltage on a gate electrode and then subsequently altered by exposure to detected charged molecules. We demonstrate the functionality of the device by performing label-free optical detection of DNA molecules. In this experiment, a monolayer of strongly cationic charged polymer polyethylenimine is used to shift the charge state of near surface NV centers from negatively charged NV- to neutral NV0 or dark positively charged NV+. Immobilization of negatively charged DNA molecules on the surface of the sensor restores the NV centers charge state back to the negatively charged NV-, which is detected using confocal photoluminescence microscopy. Biochemical reactions in the microfluidic channel are characterized by electrochemical impedance spectroscopy. The use of the developed electrochemical device can also be extended to nuclear magnetic resonance spin sensing.
