PLOS ONE: [sortOrder=DATE_NEWEST_FIRST, sort=Date, newest first, filterJournals=PLoSONE, q=subject:"Fluidics"]PLOShttps://journals.plos.org/plosone/webmaster@plos.orgaccelerating the publication of peer-reviewed sciencehttps://journals.plos.org/plosone/search/feed/atom?sortOrder=DATE_NEWEST_FIRST&unformattedQuery=subject:%22Fluidics%22&sort=Date,+newest+first&filterJournals=PLoSONEAll PLOS articles are Open Access.https://journals.plos.org/plosone/resource/img/favicon.icohttps://journals.plos.org/plosone/resource/img/favicon.ico2024-03-19T10:20:28ZMulti-domain automated patterning of DNA-functionalized hydrogelsMoshe RubanovJoshua ColeHeon-Joon LeeLeandro G. Soto CordovaZachary ChenElia GonzalezRebecca Schulman10.1371/journal.pone.02959232024-02-02T14:00:00Z2024-02-02T14:00:00Z<p>by Moshe Rubanov, Joshua Cole, Heon-Joon Lee, Leandro G. Soto Cordova, Zachary Chen, Elia Gonzalez, Rebecca Schulman</p>
DNA-functionalized hydrogels are capable of sensing oligonucleotides, proteins, and small molecules, and specific DNA sequences sensed in the hydrogels’ environment can induce changes in these hydrogels’ shape and fluorescence. Fabricating DNA-functionalized hydrogel architectures with multiple domains could make it possible to sense multiple molecules and undergo more complicated macroscopic changes, such as changing fluorescence or changing the shapes of regions of the hydrogel architecture. However, automatically fabricating multi-domain DNA-functionalized hydrogel architectures, capable of enabling the construction of hydrogel architectures with tens to hundreds of different domains, presents a significant challenge. We describe a platform for fabricating multi-domain DNA-functionalized hydrogels automatically at the micron scale, where reaction and diffusion processes can be coupled to program material behavior. Using this platform, the hydrogels’ material properties, such as shape and fluorescence, can be programmed, and the fabricated hydrogels can sense their environment. DNA-functionalized hydrogel architectures with domain sizes as small as 10 microns and with up to 4 different types of domains can be automatically fabricated using ink volumes as low as 50 μL. We also demonstrate that hydrogels fabricated using this platform exhibit responses similar to those of DNA-functionalized hydrogels fabricated using other methods by demonstrating that DNA sequences can hybridize within them and that they can undergo DNA sequence-induced shape change.Spatial confinement of <i>Trypanosoma brucei</i> in microfluidic traps provides a new tool to study free swimming parasitesMariana De NizEmmanuel FrachonSamy GobaaPhilippe Bastin10.1371/journal.pone.02962572023-12-22T14:00:00Z2023-12-22T14:00:00Z<p>by Mariana De Niz, Emmanuel Frachon, Samy Gobaa, Philippe Bastin</p>
<i>Trypanosoma brucei</i> is the causative agent of African trypanosomiasis and is transmitted by the tsetse fly (<i>Glossina spp</i>.). All stages of this extracellular parasite possess a single flagellum that is attached to the cell body and confers a high degree of motility. While several stages are amenable to culture <i>in vitro</i>, longitudinal high-resolution imaging of free-swimming parasites has been challenging, mostly due to the rapid flagellar beating that constantly twists the cell body. Here, using microfabrication, we generated various microfluidic devices with traps of different geometrical properties. Investigation of trap topology allowed us to define the one most suitable for single <i>T. brucei</i> confinement within the field of view of an inverted microscope while allowing the parasite to remain motile. Chips populated with V-shaped traps allowed us to investigate various phenomena in cultured procyclic stage wild-type parasites, and to compare them with parasites whose motility was altered upon knockdown of a paraflagellar rod component. Among the properties that we investigated were trap invasion, parasite motility, and the visualization of organelles labelled with fluorescent dyes. We envisage that this tool we have named “Tryp-Chip” will be a useful tool for the scientific community, as it could allow high-throughput, high-temporal and high-spatial resolution imaging of free-swimming <i>T. brucei</i> parasites.Neural network execution using nicked DNA and microfluidicsArnav SolankiZak GriffinPurab Ranjan SutradharKarisha PradhanCaiden MerrittAmlan GangulyMarc Riedel10.1371/journal.pone.02922282023-10-19T14:00:00Z2023-10-19T14:00:00Z<p>by Arnav Solanki, Zak Griffin, Purab Ranjan Sutradhar, Karisha Pradhan, Caiden Merritt, Amlan Ganguly, Marc Riedel</p>
DNA has been discussed as a potential medium for data storage. Potentially it could be denser, could consume less energy, and could be more durable than conventional storage media such as hard drives, solid-state storage, and optical media. However, performing computations on the data stored in DNA is a largely unexplored challenge. This paper proposes an integrated circuit (IC) based on microfluidics that can perform complex operations such as artificial neural network (ANN) computation on data stored in DNA. We envision such a system to be suitable for highly dense, throughput-demanding bio-compatible applications such as an intelligent Organ-on-Chip or other biomedical applications that may not be latency-critical. It computes entirely in the molecular domain without converting data to electrical form, making it a form of <i>in-memory</i> computing on DNA. The computation is achieved by topologically modifying DNA strands through the use of enzymes called nickases. A novel scheme is proposed for representing data stochastically through the concentration of the DNA molecules that are nicked at specific sites. The paper provides details of the biochemical design, as well as the design, layout, and operation of the microfluidics device. Benchmarks are reported on the performance of neural network computation.Cortical spheroid on perfusable microvascular network in a microfluidic deviceTeal RussellQassim DirarYan LiChiwan ChiangDaniel T. LaskowitzYeoheung Yun10.1371/journal.pone.02880252023-10-19T14:00:00Z2023-10-19T14:00:00Z<p>by Teal Russell, Qassim Dirar, Yan Li, Chiwan Chiang, Daniel T. Laskowitz, Yeoheung Yun</p>
Human induced pluripotent stem cell (hiPSC)-derived brain spheroids can recapitulate the complex cytoarchitecture of the brain, as well as the genetic/epigenetic footprint of human brain development. However, hiPSC-derived 3D models such as spheroid and organoids does not have a perfusable microvascular network, which plays a vital role in maintaining homeostasis <i>in vivo</i>. With the critical balance of positive and negative angiogenic modulators, 3D microvascular network can be achieved by angiogenesis. This paper reports on a microfluidic-based three-dimensional, cortical spheroid grafted on the vascular-network. Vascular network was formed by inducing angiogenic sprouting using concentration gradient-driven angiogenic factors in the microfluidic device. We investigate critical factors for angiogenic vascular network formation with spheroid placement, including 1) a PKCα activator, phorbol-12-myristate-13-acetate (PMA); 2) orientation of endothelial cells under perfusion and permeability of vascular network; 3) effect of extracellular matrix (ECM) types and their densities on angiogenesis; and 4) integration with cortical spheroid on vascular network. This paper demonstrates proof of concept for the potential utility of a membrane-free <i>in vitro</i> cortical spheroid tissue construct with perfusable microvascular network that can be scaled up to a high throughput platform. It can provide a cost-effective alternative platform to animal testing by modeling brain diseases and disorders, and screening drugs.Digital process control of multi-step assays on centrifugal platforms using high-low-high rotational-pulse triggered valvingPhilip L. EarlyNiamh A. KilcawleyNiamh A. McArdleMarine RenouSinéad M. KearneyRohit MishraNikolay DimovMacdara T. GlynnJens DucréeDavid J. Kinahan10.1371/journal.pone.02911652023-09-08T14:00:00Z2023-09-08T14:00:00Z<p>by Philip L. Early, Niamh A. Kilcawley, Niamh A. McArdle, Marine Renou, Sinéad M. Kearney, Rohit Mishra, Nikolay Dimov, Macdara T. Glynn, Jens Ducrée, David J. Kinahan</p>
Due to their capability for comprehensive sample-to-answer automation, the interest in centrifugal microfluidic systems has greatly increased in industry and academia over the last quarter century. The main applications of these “Lab-on-a-Disc” (LoaD) platforms are in decentralised bioanalytical point-of-use / point-of-care testing. Due to the unidirectional and omnipresent nature of the centrifugal force, advanced flow control is key to coordinate multi-step / multi-reagent assay formats on the LoaD. Formerly, flow control was often achieved by capillary burst valves which require gradual increments of the spin speed of the system-innate spindle motor. Recent advanced introduced a flow control scheme called ’rotational pulse actuated valves’. In these valves the sequence of valve actuation is determined by the architecture of the disc while actuation is triggered by freely programmable upward spike (i.e. Low-High-Low (LHL)) in the rotational frequency. This paradigm shift from conventional ‘analogue’ burst valves to ‘digital’ pulsing significantly increases the number of sequential while also improving the overall robustness of flow control. In this work, we expand on these LHL valves by introducing High-Low-High (HLH) pulse-actuated (PA) valving which are actuated by ’downward’ spike in the disc spin-rate. These HLH valves are particularly useful for high spin-rate operations such as centrifugation of blood. We introduce two different HLH architectures and then combine the most promising with LHL valves to implement the time-dependent liquid handling protocol underlying a common liver function test panel.Microfluidic delivery of cutting enzymes for fragmentation of surface-adsorbed DNA moleculesJulia BudassiNaHyun ChoAnthony Del ValleJonathan Sokolov10.1371/journal.pone.02500542023-09-06T14:00:00Z2023-09-06T14:00:00Z<p>by Julia Budassi, NaHyun Cho, Anthony Del Valle, Jonathan Sokolov</p>
We describe a method for fragmenting, in-situ, surface-adsorbed and immobilized DNAs on polymethylmethacrylate(PMMA)-coated silicon substrates using microfluidic delivery of the cutting enzyme DNase I. Soft lithography is used to produce silicone elastomer (Sylgard 184) gratings which form microfluidic channels for delivery of the enzyme. Bovine serum albumin (BSA) is used to reduce DNase I adsorption to the walls of the microchannels and enable diffusion of the cutting enzyme to a distance of 10mm. Due to the DNAs being immobilized, the fragment order is maintained on the surface. Possible methods of preserving the order for application to sequencing are discussed.Rapid and sensitive detection of gram-negative bacteria using surface-immobilized polymyxin BHyun-Jin KangSang-Hoon LeeHan-Shin KimYong Woo JungHee-Deung Park10.1371/journal.pone.02905792023-08-28T14:00:00Z2023-08-28T14:00:00Z<p>by Hyun-Jin Kang, Sang-Hoon Lee, Han-Shin Kim, Yong Woo Jung, Hee-Deung Park</p>
Although detection of gram-negative bacteria (GNB) in body fluids is important for clinical purpose, traditional gram staining and other recently developed methods have inherent limitations in terms of accuracy, sensitivity, and convenience. To overcome the weakness, this study proposed a method detecting GNB based on specific binding of polymyxin B (PMB) to lipopolysaccharides (LPS) of GNB. Fluorescent microscopy demonstrated that surface immobilized PMB using a silane coupling agent was possible to detect fluorescent signal produced by a single <i>Escherichia coli</i> (a model GNB) cell. Furthermore, the signal was selective enough to differentiate between GNB and gram-positive bacteria. The proposed method could detect three cells per ml within one hour, indicating the method was very sensitive and the sensing was rapid. These results suggest that highly multifold PMB binding on each GNB cell occurred, as millions of LPS are present on cell wall of a GNB cell. Importantly, the principle used in this study was realized in a microfluidic chip for a sample containing <i>E</i>. <i>coli</i> cells suspended in porcine plasma, demonstrating its potential application to practical uses. In conclusion, the proposed method was accurate, sensitive, and convenient for detecting GNB, and could be applied clinically.An image-guided microfluidic system for single-cell lineage trackingMahmut Aslan KamilCamille FourneauxAlperen YilmazStavrakis StavrosRomuald ParmentierAndras PaldiSandrine Gonin-GiraudAndrew J. deMelloOlivier Gandrillon10.1371/journal.pone.02886552023-08-01T14:00:00Z2023-08-01T14:00:00Z<p>by Mahmut Aslan Kamil, Camille Fourneaux, Alperen Yilmaz, Stavrakis Stavros, Romuald Parmentier, Andras Paldi, Sandrine Gonin-Giraud, Andrew J. deMello, Olivier Gandrillon</p>
Cell lineage tracking is a long-standing and unresolved problem in biology. Microfluidic technologies have the potential to address this problem, by virtue of their ability to manipulate and process single-cells in a rapid, controllable and efficient manner. Indeed, when coupled with traditional imaging approaches, microfluidic systems allow the experimentalist to follow single-cell divisions over time. Herein, we present a valve-based microfluidic system able to probe the decision-making processes of single-cells, by tracking their lineage over multiple generations. The system operates by trapping single-cells within growth chambers, allowing the trapped cells to grow and divide, isolating sister cells after a user-defined number of divisions and finally extracting them for downstream transcriptome analysis. The platform incorporates multiple cell manipulation operations, image processing-based automation for cell loading and growth monitoring, reagent addition and device washing. To demonstrate the efficacy of the microfluidic workflow, 6C2 (chicken erythroleukemia) and T2EC (primary chicken erythrocytic progenitors) cells are tracked inside the microfluidic device over two generations, with a cell viability rate in excess of 90%. Sister cells are successfully isolated after division and extracted within a 500 nL volume, which was demonstrated to be compatible with downstream single-cell RNA sequencing analysis.Clinical sensitivity and specificity of a high-throughput microfluidic nano-immunoassay combined with capillary blood microsampling for the identification of anti-SARS-CoV-2 Spike IgG serostatusGrégoire MichielinFatemeh ArefiOlha PuhachMathilde BellonPascale Sattonnet-RocheArnaud G. L’HuillierIsabella EckerleBenjamin MeyerSebastian J. Maerkl10.1371/journal.pone.02831492023-03-23T14:00:00Z2023-03-23T14:00:00Z<p>by Grégoire Michielin, Fatemeh Arefi, Olha Puhach, Mathilde Bellon, Pascale Sattonnet-Roche, Arnaud G. L’Huillier, Isabella Eckerle, Benjamin Meyer, Sebastian J. Maerkl</p>
Objectives <p>We evaluate the diagnostic performance of dried blood microsampling combined with a high-throughput microfluidic nano-immunoassay (NIA) for the identification of anti-SARS-CoV-2 Spike IgG seropositivity.</p> Methods <p>We conducted a serological study among 192 individuals with documented prior SARS-CoV-2 infection and 44 SARS-CoV-2 negative individuals. Participants with prior SARS-CoV-2 infection had a long interval of 11 months since their qRT-PCR positive test. Serum was obtained after venipuncture and tested with an automated electrochemiluminescence anti-SARS-CoV-2 S total Ig reference assay, a commercial ELISA anti-S1 IgG assay, and the index test NIA. In addition, 109 participants from the positive cohort and 44 participants from the negative cohort participated in capillary blood collection using three microsampling devices: Mitra, repurposed glucose test strips, and HemaXis. Samples were dried, shipped by regular mail, extracted, and measured with NIA.</p> Results <p>Using serum samples, we achieve a clinical sensitivity of 98·33% and specificity of 97·62% on NIA, affirming the high performance of NIA in participants 11 months post infection. Combining microsampling with NIA, we obtain a clinical sensitivity of 95·05% using Mitra, 61·11% using glucose test strips, 83·16% using HemaXis, and 91·49% for HemaXis after automated extraction, without any drop in specificity.</p> Discussion <p>High sensitivity and specificity was demonstrated when testing micro-volume capillary dried blood samples using NIA, which is expected to facilitate its use in large-scale studies using home-based sampling or samples collected in the field.</p>Development of a programmable magnetic agitation device to maintain colloidal suspension of cells during microfluidic syringe pump perfusionTommy PuttrichSteven O’DonnellSing-Wan WongMiiri KotcheAnthony E. FelderJae-Won Shin10.1371/journal.pone.02825632023-03-08T14:00:00Z2023-03-08T14:00:00Z<p>by Tommy Puttrich, Steven O’Donnell, Sing-Wan Wong, Miiri Kotche, Anthony E. Felder, Jae-Won Shin</p>
Droplet-based microfluidic devices have been used to achieve homogeneous cell encapsulation, but cells sediment in a solution, leading to heterogeneous products. In this technical note, we describe automated and programmable agitation device to maintain colloidal suspensions of cells. We demonstrate that the agitation device can be interfaced with a syringe pump for microfluidic applications. Agitation profiles of the device were predictable and corresponded to device settings. The device maintains the concentration of cells in an alginate solution over time without implicating cell viability. This device replaces manual agitation, and hence is suitable for applications that require slow perfusion for a longer period of time in a scalable manner.A novel microfluidic compact disc to investigate electrochemical property changes between artificial and real salivary samples mixed with mouthwashes using electrical impedance analysisAung ThihaFatimah IbrahimKarunan JosephBojan PetrovićSanja KojićNuraina Anisa DahlanNurul Fauzani JamaluddinSaima QureshiGoran M. Stojanović10.1371/journal.pone.02803812023-02-16T14:00:00Z2023-02-16T14:00:00Z<p>by Aung Thiha, Fatimah Ibrahim, Karunan Joseph, Bojan Petrović, Sanja Kojić, Nuraina Anisa Dahlan, Nurul Fauzani Jamaluddin, Saima Qureshi, Goran M. Stojanović</p>
Diagnosing oral diseases at an early stage may lead to better preventive treatments, thus reducing treatment burden and costs. This paper introduces a systematic design of a microfluidic compact disc (CD) consisting of six unique chambers that run simultaneously from sample loading, holding, mixing and analysis. In this study, the electrochemical property changes between real saliva and artificial saliva mixed with three different types of mouthwashes (i.e. chlorhexidine-, fluoride- and essential oil (Listerine)-based mouthwashes) were investigated using electrical impedance analysis. Given the diversity and complexity of patient’s salivary samples, we investigated the electrochemical impedance property of healthy real saliva mixed with different types of mouthwashes to understand the different electrochemical property which could be a foundation for diagnosis and monitoring of oral diseases. On the other hand, electrochemical impedance property of artificial saliva, a commonly used moisturizing agent and lubricant for the treatment of xerostomia or dry mouth syndrome was also studied. The findings indicate that artificial saliva and fluoride-based mouthwash showed higher conductance values compared to real saliva and two other different types of mouthwashes. The ability of our new microfluidic CD platform to perform multiplex processes and detection of electrochemical property of different types of saliva and mouthwashes is a fundamental concept for future research on salivary theranostics using point-of-care microfluidic CD platform.Theory and practice of using cell strainers to sort <i>Caenorhabditis elegans</i> by sizeVincent J. LanierAmanda M. WhiteSerge FaumontShawn R. Lockery10.1371/journal.pone.02809992023-02-09T14:00:00Z2023-02-09T14:00:00Z<p>by Vincent J. Lanier, Amanda M. White, Serge Faumont, Shawn R. Lockery</p>
The nematode <i>Caenorhabditis elegans</i> is a model organism widely used in basic, translational, and industrial research. <i>C</i>. <i>elegans</i> development is characterized by five morphologically distinct stages, including four larval stages and the adult stage. Stages differ in a variety of aspects including size, gene expression, physiology, and behavior. Enrichment for a particular developmental stage is often the first step in experimental design. When many hundreds of worms are required, the standard methods of enrichment are to grow a synchronized population of hatchlings for a fixed time, or to sort a mixed population of worms according to size. Current size-sorting methods have higher throughput than synchronization and avoid its use of harsh chemicals. However, these size-sorting methods currently require expensive instrumentation or custom microfluidic devices, both of which are unavailable to the majority <i>C</i>. <i>elegans</i> laboratories. Accordingly, there is a need for inexpensive, accessible sorting strategies. We investigated the use of low-cost, commercially available cell strainers to filter <i>C</i>. <i>elegans</i> by size. We found that the probability of recovery after filtration as a function of body size for cell strainers of three different mesh sizes is well described by logistic functions. Application of these functions to predict filtration outcomes revealed non-ideal properties of filtration of worms by cell strainers that nevertheless enhanced filtration outcomes. Further, we found that serial filtration using a pair of strainers that have different mesh sizes can be used to enrich for particular larval stages with a purity close to that of synchronization, the most widely used enrichment method. Throughput of the cell strainer method, up to 14,000 worms per minute, greatly exceeds that of other enrichment methods. We conclude that size sorting by cell strainers is a useful addition to the array of existing methods for enrichment of particular developmental stages in <i>C</i>. <i>elegans</i>.Rapid quantification assay of hepatitis B virus DNA in human serum and plasma by Fully Automated Genetic Analyzer μTASWako g1Moto WatanabeHidenori ToyodaTomohisa Kawabata10.1371/journal.pone.02781432023-02-09T14:00:00Z2023-02-09T14:00:00Z<p>by Moto Watanabe, Hidenori Toyoda, Tomohisa Kawabata</p>
Real-time monitoring of serum hepatitis B virus (HBV) levels is essential for the management of patients with chronic HBV infection in clinical practice, including monitoring the resistance of anti-HBV nucleotide analog or the detection of HBV reactivation. In this context, serum HBV deoxyribonucleic acid (DNA) quantification should be rapidly measured. A rapid HBV DNA quantification assay was established on the Fully Automated Genetic Analyzer, μTASWako g1. The assay performs automated sample preparation and DNA extraction, followed by the amplification and detection of quantitative polymerase chain reaction (PCR) combined with capillary electrophoresis (qPCR-CE) on integrated microfluidic chip. This study aimed to evaluate the analytical and clinical performance of HBV DNA assay on the μTASWako g1 platform in human serum and EDTA-plasma. The HBV DNA assay has a linear quantitative range from 20 to 10<sup>8</sup> IU/mL of HBV DNA with standard deviation (SD) of ≤0.14 log<sub>10</sub> IU/mL. The limits of detection of the assay were 4.18 for the serum and 4.35 for EDTA-plasma. The HBV assay demonstrated the equivalent performance in both human serum and EDTA-plasma matrices. The HBV genotypes A to H were detected with an accuracy of ±0.34 log<sub>10</sub> IU/mL. In quantification range, the HBV DNA assay was correlated with Roche cobas AmpliPrep/cobas TaqMan Ver2.0 (CAP/CTM v2) (<i>r</i> = 0.964). The mean difference (μTASWako g1–CAP/CTM v2) of the reported HBV DNA was −0.01 log<sub>10</sub> IU/mL. Overall, the sensitivity, accuracy, and precision of the μTASWako g1 HBV assay were comparable to the existing commercial HBV DNA assay, and the assay can be completed within 110 min. This evaluation suggests that the HBV DNA assay on the μTASWako g1 is potentially applied for alternative method of the HBV viral load test, in particular with the advantage of the HBV DNA result availability within 2 h, improving the HBV infection management.Spatially selective cell treatment and collection for integrative drug testing using hydrodynamic flow focusing and shiftingXu WangJingtian ZhengMaheshwar Adiraj IyerAdam Henry SzmelterDavid T. EddingtonSteve Seung-Young Lee10.1371/journal.pone.02791022023-01-17T14:00:00Z2023-01-17T14:00:00Z<p>by Xu Wang, Jingtian Zheng, Maheshwar Adiraj Iyer, Adam Henry Szmelter, David T. Eddington, Steve Seung-Young Lee</p>
Hydrodynamic focusing capable of readily producing and controlling laminar flow facilitates drug treatment of cells in existing microfluidic culture devices. However, to expand applications of such devices to multiparameter drug testing, critical limitations in current hydrodynamic focusing microfluidics must be addressed. Here we describe hydrodynamic focusing and shifting as an advanced microfluidics tool for spatially selective drug delivery and integrative cell-based drug testing. We designed and fabricated a co-flow focusing, three-channel microfluidic device with a wide cell culture chamber. By controlling inlet flow rates of sample and two side solutions, we could generate hydrodynamic focusing and shifting that mediated precise regulation of the path and width of reagent and drug stream in the microfluidic device. We successfully validated a hydrodynamic focusing and shifting approach for spatially selective delivery of DiI, a lipophilic fluorophore, and doxorubicin, a chemotherapeutic agent, to tumor cells in our device. Moreover, subsequent flowing of a trypsin EDTA solution over the cells that were exposed to doxorubicin flow allowed us to selectively collect the treated cells. Our approach enabled downstream high-resolution microscopy of the cell suspension to confirm the nuclear delivery of doxorubicin into the tumor cells. In the device, we could also evaluate <i>in situ</i> the cytotoxic effect of doxorubicin to the tumor cells that were selectively treated by hydrodynamic flow focusing and shifting. These results show that hydrodynamic focusing and shifting enable a fast and robust approach to spatially treat and then collect cells in an optimized microfluidic device, offering an integrative assay tool for efficient drug screening and discovery.Rapid identification and quantitation of single plant seed allergen using paper-based microfluidicsXiaodong SunYongxin LiuBing NiuQin ChenXueen Fang10.1371/journal.pone.02667752022-12-12T14:00:00Z2022-12-12T14:00:00Z<p>by Xiaodong Sun, Yongxin Liu, Bing Niu, Qin Chen, Xueen Fang</p>
Nucleic acid amplification is a sensitive and powerful tool for allergen detection. However, it is limited due to the relatively cumbersome methods required to extract nucleic acids from single plant seed allergen (e.g. peanut and soybean). In view of this, an approach of extracting nucleic acid with untreated glass-fiber paper (paper-based microfluidics) was applied for nucleic acid capture and purification from plant seed allergen and commercial products. After cut by hollow cylindrical cutter, a certain size the paper chip it used to absorb DNA. And this paper-based microfluidics with DNA was directly applied for amplification by loop-mediated isothermal amplification (LAMP). To evaluate the adsorption performance of paper chip to DNA, CTAB and SDS method were used as comparisons. From amplification results, the established technique has good specificity, high repeatability (C.V. values are 4.41% and 6.17% for peanut and soybean) and favorable sensitivity (7.39 ng/μL or peanut and 6.6 ng/μL for soybean), and successfully used for commercial products (2 kinds of candy and 2 kinds of cakes containing peanut, and 2 kinds of drinks, candy and 2 kinds of biscuits containing soybean). This speed and flexible detection method makes it suit for applications in point-of-care (POC) detection at different scenario, such as custom house and import port.