Lab On A Chip

Novel coronavirus disease (COVID-19) has been spread in 213 countries and created an emergency situation in around the world. Coronavirus is a group of single-stranded RNA enveloped virus which causes severe respiratory infection in the infected individual. Nowadays, coronavirus has become a leading cause of death in the world. Efficient diagnosis is an essential step before starting the best possible treatment. For the diagnosis of coronavirus mainly 3 methods are reported such as RT-PCR method, Regular LAMP-based methods and Serology based tests. Based on the above methods, various diagnostic kits has been developed by different countries. This review contains the list of diagnostic kits approved by various countries, their working mechanism and time taken to give result along with sampling procedure and major precautions which is most important during the diagnosis process. The worldwide R & D (research and development) will definitely lead to find an efficient and rapid diagnostic tool for the treatment of COVID-19.

Sequencing the genomes of individual cells enables the direct determination of genetic heterogeneity amongst cells within a population. We have developed an injection-moulded valveless microfluidic device in which single cells from colorectal cancer derived cell lines (LS174T, LS180 and RKO) and fresh colorectal tumors have been individually trapped, their genomes extracted and prepared for sequencing using multiple displacement amplification (MDA). Ninety nine percent of the DNA sequences obtained mapped to a reference human genome, indicating that there was effectively no contamination of these samples from non-human sources. In addition, most of the reads are correctly paired, with a low percentage of singletons (0.17 ± 0.06%) and we obtain genome coverages approaching 90%. To achieve this high quality, our device design and process shows that amplification can be conducted in microliter volumes as long as the lysis is in sub-nanoliter volumes. Our data thus demonstrates that hig...

Physically crosslinked layered microscale biomembranes from pure chitosan are demonstrated for pH-triggered release functionalized mesoporous silica nanoparticles. The work opens the door to synthesis of complex nano-enhanced micro membranes.

Este artículo revisa una serie de planteos que realizamos en 2013 sobre los distintos factores que intervienen y condicionan el desarrollo de la violencia en el fútbol argentino. En dicho análisis incluimos un conjunto de propuestas tendientes al diálogo con el sector de las políticas públicas nacionales, con miras a generar una solución al problema. Hoy, el número de heridos y muertos asociados al hecho futbolístico continúa creciendo. Según datos publicados por la Asociación Civil Salvemos al Fútbol, 332 personas han muerto en Argentina en situaciones relacionadas con el fútbol. Nuestro estudio sobre el problema de «las violencias» (porque no existe un solo responsable ni una sola manera de expresar la violencia) involucra una multiplicidad de actores sociales de distintos espacios (barras, hinchas comunes, dirigentes, políticos, periodistas, fuerzas de seguridad, representantes del Poder Judicial) y diferentes factores (históricos, simbólicos, políticos, de seguridad, organizativ...

We report observations of the self-assembly of coated droplets into regular clusters at the sudden expansion of a microfluidic channel. A double emulsion consisting of a regular train of coated microdroplets was created upstream of the channel expansion, so that the inter-drop distance, droplet length, velocity and coating thickness could be varied by imposing different inlet pressures, albeit not independently. Provided that the enlarged channel remains sufficiently confined to prohibit propagation in double file, droplets can assemble sequentially into regular linear clusters at the expansion. Droplets join a cluster via the coalescence of their coating film with that of the group ahead. This coalescence occurs when the droplets approach each other to within a critical distance at the expansion, enabled by hydrodynamic interactions within the train. Clusters comprising a finite number of droplets are obtained because reconfiguration of the droplet assembly during coalescence incre...

The drive to improve the performance and reduce the cost of electronic, photonic and fluidic devices is starting to focus on the use of materials that are exotic for these applications but actually readily available in other fields. In this talk the use of paper in biochip and other applications will be reviewed. Paper is a very attractive material for many device applications: very low cost, available in almost any size, versatile surface finishes, portable and flexible. From an environmental point of view, paper is a renewable resource and is readily disposable (incineration, biodegradable). Applications of paper-based electronics currently being considered or investigated include biochips, sensors, communication circuits, batteries, smart packaging, displays. The potential advantages of paper-based devices are in many cases very compelling. For example, biochips fabricated on paper can use the capillary properties of paper to operate without the need of external power sources, gr...

Serial femtosecond crystallography is a new method for protein structure determination utilizing intense and destructive X-ray pulses generated by free-electron lasers. The approach requires the means to deliver hydrated protein crystals to a focused X-ray beam and replenish them at the repetition rate of the pulses. A liquid-jet sample delivery system where a gas dynamic virtual nozzle is printed directly on a silicon-glass microfluidic chip using a 2-photon-polymerization 3D printing process is implemented. This allows for rapid prototyping and high-precision production of nozzles to suit the characteristics of a particular sample and opens up the possibility for high-throughput and versatile sample delivery systems that can integrate microfluidic components for sample detection, characterisation, or control. With the hybrid system described here, stable liquid jets with diameters between 1.5 µm at liquid flow rate of 1.5 µl/min and more than 20 µm at liquid flow rate of 100 µl/mi...

A fundamental challenge of biology is to understand the vast heterogeneity of cells, particularly how cellular composition, structure, and morphology are linked to cellular physiology. Unfortunately, conventional technologies are limited in uncovering these relations. We present a machine-intelligence technology based on a radically different architecture that realizes real-time image-based intelligent cell sorting at an unprecedented rate. This technology, which we refer to as intelligent image-activated cell sorting, integrates high-throughput cell microscopy, focusing, and sorting on a hybrid software-hardware data-management infrastructure, enabling real-time automated operation for data acquisition, data processing, decision-making, and actuation. We use it to demonstrate real-time sorting of microalgal and blood cells based on intracellular protein localization and cell-cell interaction from large heterogeneous populations for studying photosynthesis and atherothrombosis, resp...

Abstract: We used thermocapillary stresses induced locally by laser on flowing drops to build high throughput drop switchers and sorters for digital microfluidics. Since the laser is disconnected to the chip, the method does not require dedicated micropatterning. We show switching efficiencies of 100 % for

Formaldehyde (HCHO), a chemical compound used in the fabrication process of a broad range of household products, is present indoors as an airborne pollutant due to its high volatility caused by its low boiling point ( T = − 19 °C). Miniaturization of analytical systems towards palm-held devices has the potential to provide more efficient and more sensitive tools for real-time monitoring of this hazardous air pollutant. This work presents the initial steps and results of the prototyping process towards on-chip integration of HCHO sensing, based on the Hantzsch reaction coupled to the fluorescence optical sensing methodology. This challenge was divided into two individually addressed problems: (1) efficient airborne HCHO trapping into a microfluidic context and (2) 3,5–diacetyl-1,4-dihydrolutidine (DDL) molecular sensing in low interrogation volumes. Part (2) was addressed in this paper by proposing, fabricating, and testing a fluorescence detection system based on an ultra-low light ...

Scattering media have always been looked upon as an obstacle in imaging. Various methods, ranging from holography to phase compensation as well as to correlation techniques, have been proposed to cope with this obstacle. We, on the other hand, have a different understanding about the role of the diffusing media. In this paper we propose and demonstrate a ‘scatter-plate microscope’ that utilizes the diffusing property of the random medium for imaging micro structures with diffraction-limited resolution. The ubiquitous property of the speckle patterns permits to exploit the scattering medium as an ultra-thin lensless microscope objective with a variable focal length and a large working distance. The method provides a light, flexible and cost effective imaging device as an alternative to conventional microscope objectives. In principle, the technique is also applicable to lensless imaging in UV and X-ray microscopy. Experiments were performed with visible light to demonstrate the micro...

Scattering media have always been looked upon as an obstacle in imaging. Various methods, ranging from holography to phase compensation as well as to correlation techniques, have been proposed to cope with this obstacle. We, on the other hand, have a different understanding about the role of the diffusing media. In this paper we propose and demonstrate a ‘scatter-plate microscope’ that utilizes the diffusing property of the random medium for imaging micro structures with diffraction-limited resolution. The ubiquitous property of the speckle patterns permits to exploit the scattering medium as an ultra-thin lensless microscope objective with a variable focal length and a large working distance. The method provides a light, flexible and cost effective imaging device as an alternative to conventional microscope objectives. In principle, the technique is also applicable to lensless imaging in UV and X-ray microscopy. Experiments were performed with visible light to demonstrate the micro...

Utilizing surfactants and surface tension effects, smart droplets have been previously reported that can solve complex mazes1, are capable of photo chemo-propulsion2 or can be guided or repelled by light3. In contrast, herein we present self-propelled ionic liquid droplets composed solely of an ionic liquid (IL), namely trihexyl(tetradecyl)phosphonium chloride ([P6,6,6,14][Cl]), that are guided to specific destinations inside open fluidic networks through electro-stimulation. The movement of these droplets is controlled by creating conditions which result in a biased release of the cationic surfactant [P6,6,6,6,14]+, component of the IL. Once released the surfactant lowers the surface tension of the aqueous solution. Liquid flows from areas of low surface tension to high surface tension, phenomena known as the marangoni effect. The rate of [P6,6,6,14]+ release depends on the solubility of the closely associated Cl- anion, as the formation of free [P6,6,6,14]+ (the active surfactant ...

Guiding the interaction of single cells acting as partners in heterotypic interactions (e.g., effectors and targets of immune lysis) and monitoring the outcome of these interactions are regarded as crucial biomedical achievements. In this study, taking advantage of a dielectrophoresis (DEP)-based Laboratory-on-a-chip platform (the DEPArray), we show that it is possible to generate closed DEP cages entrapping CTLs and NK cells as either single cells or clusters; reversibly immobilize a single virus-presenting or tumor cell within the chip at a selected position; move cages and their content to predetermined spatial coordinates by software-guided routing; force a cytotoxic effector to physically interact with a putative target within a secluded area by merging their respective cages; generate cages containing effector and target cells at predetermined E:T ratios; accurately assess cytotoxicity by real-time quantitation of the release kinetics of the fluorescent dye calcein from target...

A multi-functional microfluidic platform was fabricated to demonstrate the feasibility of on-chip electroporation integrated with dielectrophoresis (DEP) and alternating-current-electro-osmosis (ACEO) assisted cell/particle manipulation. A spatial gradient of electroporation parameters was generated within a microchamber array and validated using normal human dermal fibroblast (NHDF) cells and red fluorescent protein-expressing human umbilical vein endothelial cells (RFP-HUVECs) with various fluorescent indicators. The edge of the bottom electrode, coinciding with the microchamber entrance, may act as an on-demand gate, functioning under either positive or negative DEP. In addition, at sufficiently low activation frequencies, ACEO vortices can complement the DEP to contribute to a rapid trapping/alignment of particles. As such, results clearly indicate that the microfluidic platform has the potential to achieve high-throughput screening for electroporation with spatial control and u...

Within the human blood immune cells assume specific functions to modulate and control the human immune response. Consequently, they are used for the diagnosis and treatment of autoimmune and hematologic diseases. Traceless Affinity Cell Selection Technology (Fab-TACS® technology) is a new method for selective isolation of specific immune cells from blood samples. Currently, the technology is used in a 60 mL syringe-like cartridge, which is operated by a control unit (Fabian®). Nevertheless, diagnostic applications require the reduction of the sample volume to several microliters. Therefore, we developed a cartridge for the purification of small blood volumes with the aid of suitable scaling and simulation methods. By implementing a multi domain physical systems model of the established cartridge we could simulate the separation process. Based on that a microfluidic cartridge was designed and several prototypes were manufactured. To operate the microfluidic cartridge a setup and soft...

Microfluidic devices have been widely used in mechanical, biomedical, chemical, and materials research. As a result, it is becoming increasingly important to have a cheap, fast, and reliable method for rapid microfabrication. However, prototyping of microfluidic devices typically suffers from the high initial cost, low resolution, rough surface finish, and long turn-around time. Here we present a strategic approach to closed-loop control of deterministic fabrication process based on in-situ image analysis called image-guided in-situ maskless lithography (IGIs-ML). Using the closed-loop control along with flush-flow functionality and leveraging the swelling behavior of the photocurable polymer, we demonstrate the fabrication of sub-micron high aspect ratio channels (800 nm width and >10 µm height) close to the light diffraction limit. This outperforms any reported rapid prototyping platforms which can typically reach tens of µm in channel width. Such dimensional capability is even...

This paper reports a high-throughput n × m well array PCR chip with an accurate and reliable method for sample loading and primers mixing. PCR mixture could be precisely introduced into each reaction chamber, which was prespotted and dried up with each primer set, by sucking the air through PDMS gas permeable wall. In this approach, the mixing of primer and sample at constant ratio was achieved and an equal amplification rate at an unique condition was ensured across the reaction chambers. Our method can be used to develop multi-target sample amplification chips for diagnostic applications.

С усложнением горно-геологических условий качественный отбор проб пластовых флюидов становится все более трудной задачей, для ее решения требуются новые технологии и глубокое понимание физико-химических процессов, протекающих в пласте и скважине. Использование глубинных пробоотборников с азотной компенсацией давления – относительно новое для Российской Федерации направление, которое могут предложить сервисные компании для решения данной задачи. Однако отсутствие четких критериев обоснования необходимости использования дорогостоящих компенсаторных пробоотборников приводит к сдерживанию их применения. В данной статье в качестве таких критериев предложено использовать результаты оценки стабильности асфальтенов (степени вероятности отложений асфальтенов). Приведено описание разработанного алгоритма экспертной оценки необходимости применения компенсаторного отбора.

We demonstrate that the integration of complex human synovial organ cultures in a lab-on-a-chip provides reproducible and reliable information on how systemic stress factors affect synovial tissue architectures using light scatter biosensing.

Millions of people have been affected ever since the emergence of the corona virus disease of 2019 (COVID-19) outbreak, leading to an urgent need for antiviral drug and vaccine development. Current experimentation on traditional two-dimensional culture (2D) fails to accurately mimic the in vivo microenvironment for the disease, while in vivo animal model testing does not faithfully replicate human COVID-19 infection. Human-based three-dimensional (3D) cell culture models such as spheroids, organoids, and organ-on-a-chip present a promising solution to these challenges. In this report, we review the recent 3D in vitro lung models used in COVID-19 infection and drug screening studies and highlight the most common types of natural and synthetic polymers used to generate 3D lung models.

Background Point-of-care glucose-6-phosphate dehydrogenase (G6PD) testing has the potential to make the use of radical treatment for vivax malaria safer and more effective. Widespread use of G6PD tests as part of malaria case management has been limited, in part due to due concerns regarding product usability, user training, and supervision. This study seeks to assess how well end users can understand the Standard™ G6PD Test (SD Biosensor, Suwon, South Korea) workflow, result output, and label after training. This will ultimately help inform test registration and introduction. Methods Potential G6PD test users who provide malaria case management at three sites in Brazil, Ethiopia, and India were trained on the use of the SD Biosensor Standard G6PD Test and assessed based on their ability to understand the test workflow and interpret results. The assessment was done through a questionnaire, designed to assess product usability against key technical product specifications and fulfill ...

All flowering plants have evolved through multiple rounds of polyploidy throughout the evolutionary process. Intergenomic interactions between subgenomes in polyploid plants are predicted to induce chromatin modifications such as histone modifications to regulate expression of gene homoeologs.Nicotiana benthamianais an ancient allotetraploid plant with ecotypes collected from climatically diverse regions of Australia. Studying the chromatin landscape of this unique collection will likely shed light on the importance of chromatin modifications in gene regulation in polyploids as well its implications in adaptation of plants in environmentally diverse conditions. Generally, chromatin immunoprecipitation and high throughput DNA sequencing (ChIP-seq) is used to study chromatin modifications. However, due to the starchy nature of matureN. benthamianaleaves, previously published protocols were unsuitable. The higher amounts of starch in leaves that co-precipitated with nuclei hindered dow...

Here we describe a robust, microfluidic technique to generate and analyze 3D tumor spheroids, which resembles tumor microenvironment and can be used as a more effective preclinical drug testing and screening model. Monodisperse cell-laden alginate droplets were generated in polydimethylsiloxane (PDMS) microfluidic devices that combine T-junction droplet generation and external gelation for spheroid formation. The proposed approach has the capability to incorporate multiple cell types. For the purposes of our study, we generated spheroids with breast cancer cell lines (MCF-7 drug sensitive and resistant) and co-culture spheroids of MCF-7 together with a fibroblast cell line (HS-5). The device has the capability to house 1000 spheroids on chip for drug screening and other functional analysis. Cellular viability of spheroids in the array part of the device was maintained for two weeks by continuous perfusion of complete media into the device. The functional performance of our 3D tumor ...

International audienceWe present a new route for the fabrication of highly specialized micro-capillaries, based on the phenomenon of thin polymer films self-rolling. Before rolling, the surface can be patterned (chemically, topographically), permitting the fabrication of inexpensive fully functionalized capillaries