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paper based assay

Clément Niel, Christine Sinoquet, Christian Dina, Ghislain Rocheleau
Motivation: Large scale genome-wide association studies (GWAS) are tools of choice for discovering associations between genotypes and phenotypes. To date, many studies rely on univariate statistical tests for association between the phenotype and each assayed single nucleotide polymorphism (SNP). However, interaction between SNPs, namely epistasis, must be considered when tackling the complexity of underlying biological mechanisms. Epistasis analysis at large scale entails a prohibitive computational burden when addressing the detection of more than two interacting SNPs...
March 14, 2018: Bioinformatics
Dvora Izgelov, Irina Cherniakov, Gefen Aldouby Bier, Abraham J Domb, Amnon Hoffman
In recent years, Phase II metabolism, as a first pass metabolism process occurring to the parent drug, is gaining more and more attention. This is due to its acknowledged significance in drug development as well as drug-drug interactions. However, the predominant role of Phase I metabolism has always overshadowed Phase II metabolism, resulting in insufficient data regarding its mechanisms. In this paper, we investigate the effect of an advanced lipid based drug delivery system on Phase II metabolism at the intestinal level of the enterocytes monolayer...
March 14, 2018: Molecular Pharmaceutics
Mathias J Aebersold, Greta Thompson-Steckel, Adriane Joutang, Moritz Schneider, Conrad Burchert, Csaba Forró, Serge Weydert, Hana Han, János Vörös
Bottom-up neuroscience aims to engineer well-defined networks of neurons to investigate the functions of the brain. By reducing the complexity of the brain to achievable target questions, such in vitro bioassays better control experimental variables and can serve as a versatile tool for fundamental and pharmacological research. Astrocytes are a cell type critical to neuronal function, and the addition of astrocytes to neuron cultures can improve the quality of in vitro assays. Here, we present cellulose as an astrocyte culture substrate...
2018: Frontiers in Neuroscience
Akram Norouzi, Hadi Ravan, Abbas Mohammadi, Elyas Hosseinzadeh, Mahdieh Norouzi, Tahereh Fozooni
The development of powerful techniques to detect cancer cells at early stages plays a notable role in diagnosing and prognosing cancer patients and reducing mortality. This paper reports on a novel functional DNA nanoassembly capable of detecting cancer cells based on structural DNA nanotechnology. DNA nanoassemblies were constructed by the self-assembly of a DNA concatemer to a plenty of sticky-ended three-way junctions. While an aptamer moiety guided the nanoassembly to the target cancer cell, the peroxidase-mimicking DNAzymes embedded in the nanoassemblies were used as the sensing element to produce colorimetric signals...
August 9, 2018: Analytica Chimica Acta
C L Depoix, F Haegemann, F Debiève, C Hubinont
STUDY QUESTION: Is 8% O2 a better percentage of atmospheric oxygen for long-term cultures of human primary term cytotrophoblasts than the conventional 21% O2 traditionally used in cell culture? SUMMARY ANSWER: Human primary term cytotrophoblasts are able to differentiate into syncytiotrophoblasts under both atmospheric oxygen levels. WHAT IS KNOWN ALREADY: Cell culture is traditionally done under 21% O2, which is equal to a pO2 of ~160 mm Hg...
March 9, 2018: Molecular Human Reproduction
Morgan K Hoke, Kimberly A McCabe, Aaron A Miller, Thomas W McDade
OBJECTIVE: To validate a method for measuring endotoxin-core antibodies (EndoCAb) from dried blood spots (DBS)-drops of capillary whole blood collected and dried on filter paper-as an indicator of environmental enteropathy (EE) in infancy and early childhood. METHODS: A commercially available enzyme immunoassay kit was adapted for use with DBS, with optimized steps for sample elution. Technical validation included analysis of linearity/recovery, precision and reliability, lower limit of detection, and correspondence between matched plasma and DBS samples...
March 13, 2018: American Journal of Human Biology: the Official Journal of the Human Biology Council
P J Lamas-Ardisana, G Martínez-Paredes, L Añorga, H J Grande
This paper describes a new approach for the massive production of electrochemical paper-based analytical devices (ePADs). These devices are fully fabricated by screen-printing technology and consist of a lineal microfluidic channel delimited by hydrophobic walls (patterned with diluted ultraviolet screen-printing ink in chromatographic paper grade 4) and a three-electrode system (printed with carbon and/or Ag/AgCl conductive inks). The printing process was characterised and optimized for pattern each layer with only one squeeze sweep...
February 28, 2018: Biosensors & Bioelectronics
Harry D Dawson, Joan K Lunney
Pigs are a major source of food worldwide; preventing and treating their infectious diseases is essential, requiring a thorough understanding of porcine immunity. The use of pigs as models for human physiology is a growing area; progress in this area has been limited because the immune toolkit is not robust. The international community has established cluster of differentiation (CD) markers for assessing cells involved in immunity as well as characterizing numerous other cells like stem cells. Overall, for humans 419 proteins have been designated as CD markers, each reacting with a defined set of antibodies (Abs)...
February 22, 2018: Research in Veterinary Science
Marianne Smedegaard Hede, Søren Fjelstrup, Felix Lötsch, Rella Manego Zoleko, Anna Klicpera, Mirjam Groger, Johannes Mischlinger, Lilian Endame, Luzia Veletzky, Ronja Neher, Anne Katrine Wrist Simonsen, Eskild Petersen, Ghyslain Mombo-Ngoma, Magnus Stougaard, Yi-Ping Ho, Rodrigo Labouriau, Michael Ramharter, Birgitta Ruth Knudsen
Malaria is among the major threats to global health with the main burden of disease being in rural areas of developing countries where accurate diagnosis based on non-invasive samples is in high demand. We here present a novel molecular assay for detection of malaria parasites based on technology that may be adapted for low-resource settings. Moreover, we demonstrate the exploitation of this assay for detection of malaria in saliva. The setup relies on pump-free microfluidics enabled extraction combined with a DNA sensor substrate that is converted to a single-stranded DNA circle specifically by topoisomerase I expressed by the malaria causing Plasmodium parasite...
March 7, 2018: Scientific Reports
Huilei Dong, Hongfei Chen, Juqian Jiang, Hui Zhang, Chenxin Cai, Qingming Shen
Sensitive and specific detection of tumor exosomes is of great significance for early cancer diagnosis. In this paper, we report an aptamer strategy for exosome detection based on aptamer recognition-induced multi-DNA release and cyclic enzymatic amplification. First, we use aptamer-magnetic bead bioconjugates to capture tumor exosomes derived from LNCaP cells, leading to the release of three kinds of messenger DNAs (mDNAs). After magnetic separation, the released mDNAs hybridized with the probe DNAs immobilized on a gold electrode...
March 7, 2018: Analytical Chemistry
Ruiguo Wang, Wei Zhang, Peilong Wang, Xiaoou Su
An ultrasensitive paper based lateral flow assay is described for rapid and simultaneous fluorometric detection of several β-agonists including clenbuterol and its chemical analogues (mabuterol, brombuterol, cimaterol, cimbuterol, bromchlorbuterol and banbuterol). A nonspecific monoclonal antibody (mAb) against clenbuterol and its analogues was prepared and employed in a competitive immunoassay where mAb conjugated to fluorescent nanoparticles and free β-agonists compete for the binding sites. This enables rapid screening for the 7 β-agonists in a single run that takes about 8 min...
2018: Mikrochimica Acta
Karol Jaroch, Paulina Zofia Goryńska, Krzysztof Goryński, Tomasz Stefański, Barbara Bojko
The aim of the current study was to apply different strategies for generation of metabolites of combretastatin A4 (CA4) and subsequent identification of the unknown products of phase I metabolism. CA4 is a potent anti-tubulin agent currently undergoing clinical trials. The multi-tool analytical approach was based on electrochemistry (EC), in silico predictions, and in vitro studies with the use of rat liver microsomes. With the latter, two different analytical sample preparation methods were applied: protein precipitation and solid phase microextraction, both hyphenated to the liquid chromatography-high-resolution mass spectrometry platform (LC-HRMS)...
May 15, 2018: Talanta
Kefeng Wu, Changbei Ma, Zhiyi Deng, Ning Fang, Zhenwei Tang, Xingxing Zhu, Kemin Wang
In this paper, we describe a novel, label-free and nicking enzyme-assisted fluorescence signal amplification strategy that demonstrates to be cost efficient, sensitive, and unique for assaying the RNase H activity and inhibition based on G-quadruplex formation using a thioflavin T (ThT) dye. This novel assay method is able to detect RNase H with a detection limit of 0.03 U /mL and further exhibits a good linearity R2 = 0.9923 at a concentration range of 0.03-1 U/mL under optimized conditions. Moreover, the inhibition effect of gentamycin on the RNase H activity is also studied...
May 15, 2018: Talanta
Wenshu Zheng, Huiling Li, Wenwen Chen, Jiangjiang Zhang, Nuoxin Wang, Xuefeng Guo, Xingyu Jiang
A fast (1 min), straightforward but efficient, click chemistry-based system that enables the rapid detection of free copper (Cu) ions in either biological fluids or living cells without tedious pretreatment is provided. Cu can quickly induce the conjugation between graphene oxide (GO) and a fluorescent dye via click reaction. On the basis of the high specificity of bioorthogonal reaction and the effective quenching ability of GO, the assay studied in this paper can respond to Cu ions in less than 1 min with excellent selectivity and sensitivity, which is the fastest sensor for Cu as far as it is known...
March 1, 2018: Small
Bin Bin Chen, Meng Li Liu, Lei Zhan, Chun Mei Li, Chengzhi Huang
Highly selective and sensitive detection of guanosine 3'-diphosphate-5'-diphosphate (ppGpp), namely the stringent in plants or microorganisms responding to strict or extreme environmental conditions such as stress and starvation, which plays an important role in gene expression, rRNA and antibiotics production, regulations of virulence of bacteria and growth of plants, faces a great challenge owing to its extreme similarity to normal nucleotides. By modifying the surface groups of a facile two-step hydrothermal route prepared carbon dots (CDs) with terbium ions (Tb3+) in this contribution, a novel fluorescent probe with excellent properties such as highly physical and chemical stability, narrow emission and excitation wavelength-independent emission was prepared...
March 1, 2018: Analytical Chemistry
Hui Chen, Yanqi Wu, Zhu Chen, Zhili Hu, Yile Fang, Pei Liao, Yan Deng, Nongyue He
In recent years, the prevention, control, diagnosis and treatment of infectious diseases has become a global focus for public health. Traditional methods for pathogen testing have some major disadvantages including the need for highly skilled staff and expensive instrumentation, while procedural aspects are complex and sensitive to the environment. These shortcomings have greatly limited the application of traditional testing in on site pathogen detection. In this paper, we present a new point-of-care-testing (POCT) system based on magnetic nanoparticles that enable sample in-answer out (SIAO) automated real-time testing for pathogens...
December 1, 2017: Journal of Biomedical Nanotechnology
Bingqian Lin, Zhichao Guan, Yanling Song, Eunyeong Song, Zifei Lu, Dan Liu, Yuan An, Zhi Zhu, Leiji Zhou, Chaoyong Yang
Paper-based assays such as lateral flow assays are good candidates for portable diagnostics owing to their user-friendly format and low cost. In terms of analytical detection, lateral flow assays usually require dedicated instruments to obtain quantitative results. Here we demonstrate a lateral flow assay with handheld pressure meter readout for the rapid detection of disease-related protein with high sensitivity and selectivity. Based on the pressure change produced by the catalytic reaction of Pt nanoparticles related to the concentration of the target, a quantitative reaction platform was established...
February 26, 2018: Lab on a Chip
Rifat Sipahi, Günther K H Zupanc
Neural stem and progenitor cells isolated from the central nervous system form, under specific culture conditions, clonal cell clusters known as neurospheres. The neurosphere assay has proven to be a powerful in vitro system to study the behavior of such cells and the development of their progeny. However, the theory of neurosphere growth has remained poorly understood. To overcome this limitation, we have, in the present paper, developed a cellular automata model, with which we examined the effects of proliferative potential, contact inhibition, cell death, and clearance of dead cells on growth rate, final size, and composition of neurospheres...
February 22, 2018: Journal of Theoretical Biology
Annie Agnes Suganya Samson, Jungmi Lee, Joon Myong Song
In this study, we report the photo-induced electron transfer (PET) on parchment paper using riboflavin as a photo inducer and ultraviolet lamp (362 nm) as the light source. To this end, a conventional inkjet printer equipped with 4 cartridges was used. Parchment paper was found to be a favorable substrate due to its insignificant self-absorption while assisting efficient sample interaction. Upon UV-irradiation, riboflavin generated superoxide anion radical (O2 -· ) and it was available to interact with superoxide dismutase present on the same spot...
July 5, 2018: Analytica Chimica Acta
María L Scala-Benuzzi, Julio Raba, Galo J A A Soler-Illia, Rudolf J Schneider, Germán A Messina
We report a novel and innovative electrochemical paper-based immunocapture assay (EPIA) to address the need for ultrasensitive detection of emerging pollutants without regulatory status and whose effects on environment and human health are not completely yet understood. In particular, we present the application of this system towards highly sensitive detection of the emerging pollutant ethinyl estradiol (EE2). The EPIA approach is based on the use of paper microzones modified with silica nanoparticles (SNs) and anti-EE2 specific antibodies for capture and pre-concentration of EE2 from river water samples...
February 23, 2018: Analytical Chemistry
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