Lab on a Chip最新文献

{"title":"Artificial intelligence performance in testing microfluidics for point-of-care†","authors":"Mert Tunca Doganay, Purbali Chakraborty, Sri Moukthika Bommakanti, Soujanya Jammalamadaka, Dheerendranath Battalapalli, Anant Madabhushi and Mohamed S. Draz","doi":"10.1039/D4LC00671B","DOIUrl":"10.1039/D4LC00671B","url":null,"abstract":"<p >Artificial intelligence (AI) is revolutionizing medicine by automating tasks like image segmentation and pattern recognition. These AI approaches support seamless integration with existing platforms, enhancing diagnostics, treatment, and patient care. While recent advancements have demonstrated AI superiority in advancing microfluidics for point of care (POC) diagnostics, a gap remains in comparative evaluations of AI algorithms in testing microfluidics. We conducted a comparative evaluation of AI models specifically for the two-class classification problem of identifying the presence or absence of bubbles in microfluidic channels under various imaging conditions. Using a model microfluidic system with a single channel loaded with 3D transparent objects (bubbles), we challenged each of the tested machine learning (ML) (<em>n</em> = 6) and deep learning (DL) (<em>n</em> = 9) models across different background settings. Evaluation revealed that the random forest ML model achieved 95.52% sensitivity, 82.57% specificity, and 97% AUC, outperforming other ML algorithms. Among DL models suitable for mobile integration, DenseNet169 demonstrated superior performance, achieving 92.63% sensitivity, 92.22% specificity, and 92% AUC. Remarkably, DenseNet169 integration into a mobile POC system demonstrated exceptional accuracy (&gt;0.84) in testing microfluidics at under challenging imaging settings. Our study confirms the transformative potential of AI in healthcare, emphasizing its capacity to revolutionize precision medicine through accurate and accessible diagnostics. The integration of AI into healthcare systems holds promise for enhancing patient outcomes and streamlining healthcare delivery.</p>","PeriodicalId":85,"journal":{"name":"Lab on a Chip","volume":" 21","pages":" 4998-5008"},"PeriodicalIF":6.1,"publicationDate":"2024-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2024/lc/d4lc00671b?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142276035","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Vibration mixing for enhanced paper-based recombinase polymerase amplification†","authors":"Kelli N. Shimazu, Andrew T. Bender, Per G. Reinhall and Jonathan D. Posner","doi":"10.1039/D4LC00592A","DOIUrl":"10.1039/D4LC00592A","url":null,"abstract":"<p >Isothermal nucleic acid amplification tests (NAATs) are a vital tool for point-of-care (POC) diagnostics. These assays are well-suited for rapid, low-cost POC diagnostics for infectious diseases compared to traditional PCR tests conducted in central laboratories. There has been significant development of POC NAATs using paper-based diagnostic devices because they provide an affordable, user-friendly, and easy to store format; however, the difficulties in integrating separate liquid components, resuspending dried reagents, and achieving a low limit of detection hinder their use in commercial applications. Several studies report low assay efficiencies, poor detection output, and poorer limits of detection in porous membranes compared to traditional tube-based protocols. Recombinase polymerase amplification is a rapid, isothermal NAAT that is highly suited for POC applications, but requires viscous reaction conditions that has poor performance when amplifying in a porous paper membrane. In this work, we show that we can dramatically improve the performance of membrane-based recombinase polymerase amplification (RPA) of HIV-1 DNA and viral RNA by employing a coin cell-based vibration mixing platform. We achieve a limit of detection of 12 copies of DNA per reaction, nearly 50% reduction in time to threshold (from ∼10 minutes to ∼5 minutes), and an overall fluorescence output increase up to 16-fold when compared to unmixed experiments. This active mixing strategy enables reactions where the target and reaction cofactors are isolated from each other prior to the reaction. We also demonstrate amplification using a low-cost vibration motor for both temperature control and mixing, without the requirement of any additional heating components.</p>","PeriodicalId":85,"journal":{"name":"Lab on a Chip","volume":" 20","pages":" 4879-4891"},"PeriodicalIF":6.1,"publicationDate":"2024-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142273475","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dynamic sampling from ex vivo adipose tissue using droplet-based microfluidics supports separate mechanisms for glycerol and fatty acid secretion†","authors":"Md Moniruzzaman, Andresa B. Bezerra, Md Mohibullah, Robert L. Judd, James G. Granneman and Christopher J. Easley","doi":"10.1039/D4LC00664J","DOIUrl":"10.1039/D4LC00664J","url":null,"abstract":"<p >Pathologies in adipose (fat) tissue function are linked with human diseases such as diabetes, obesity, metabolic syndrome, and cancer. Dynamic, rapid release of metabolites has been observed in adipocyte cells and tissue, yet higher temporal resolution is needed to adequately study this process. In this work, a microfluidic device with precise and regular valve-automated droplet sampling, termed a microfluidic analog-to-digital converter (μADC), was used to sample secretions from ∼0.75 mm diameter adipose explants from mice, and on-chip salt water electrodes were used to merge sampled droplets with reagent droplets from two different fluorometric coupled enzyme assays. By integrating sampling and assays on-chip, either glycerol or non-esterified fatty acids (NEFA), or both, were quantified optically within merged 12 nanoliter droplets using a fluorescence microscope with as high as 20 second temporal resolution. Limits of detection were 6 μM for glycerol (70 fmol) and 0.9 μM for NEFA (10 fmol). Multiple <em>ex vivo</em> adipose tissue explants were analyzed with this system, all showing clear increases in lipolytic function after switching from feeding to fasting conditions. Enabled by high temporal resolution, lipolytic oscillations of both glycerol and NEFA were observed for the first time in the range of 0.2 to 1.6 min<small>⁻¹</small>. Continuous wavelet transform (CWT) spectrograms and burst analyses (0.1 to 4.0 pmol bursts) revealed complex dynamics, with multiplexed assays (duplex for glycerol and NEFA) from the same explants showing mostly discordant bursts. These data support separate mechanisms of NEFA and glycerol release, although the connection to intracellular metabolic oscillations remains unknown. Overall, this device allowed automated and highly precise temporal sampling of tissue explants at high resolution and programmable downstream merging with multiple assay reagents, revealing unique biological information. Such device features should be applicable to various other tissue or spheroid types and to other assay formats.</p>","PeriodicalId":85,"journal":{"name":"Lab on a Chip","volume":" 21","pages":" 5020-5031"},"PeriodicalIF":6.1,"publicationDate":"2024-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142276032","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Label-free single-cell antimicrobial susceptibility testing in droplets with concentration gradient generation†","authors":"Jae Seong Kim, Jingyeong Kim, Jae-Seok Kim, Wooseong Kim and Chang-Soo Lee","doi":"10.1039/D4LC00629A","DOIUrl":"10.1039/D4LC00629A","url":null,"abstract":"<p >Bacterial communities exhibit significant heterogeneity, resulting in the emergence of specialized phenotypes that can withstand antibiotic exposure. Unfortunately, the existence of subpopulations resistant to antibiotics often goes unnoticed during treatment initiation. Thus, it is crucial to consider the concept of single-cell antibiotic susceptibility testing (AST) to tackle bacterial infections. Nevertheless, its practical application in clinical settings is hindered by its inability to conduct AST efficiently across a wide range of antibiotics and concentrations. This study introduces a droplet-based microfluidic platform designed for rapid single-cell AST by creating an antibiotic concentration gradient. The advantage of a microfluidic platform is achieved by executing bacteria and antibiotic mixing, cell encapsulation, incubation, and enumeration of bacteria in a seamless workflow, facilitating susceptibility testing of each antibiotic. Firstly, we demonstrate the rapid determination of minimum inhibitory concentration (MIC) of several antibiotics with Gram-negative <em>E. coli</em> and Gram-positive <em>S. aureus</em>, which enables us to bypass the time-consuming bacteria cultivation, speeding up the AST in 3 h from 1 to 2 days of conventional methods. Additionally, we assess 10 clinical isolates including methicillin-resistant <em>Staphylococcus aureus</em> (MRSA) and multidrug-resistant <em>Staphylococcus aureus</em> (MDRSA) against clinically important antibiotics for analyzing the MIC, compared to the gold standard AST method from the United States Clinical and Laboratory Standards Institute (CLSI), which becomes available only after 48 h. Furthermore, by monitoring single cells within individual droplets, we have found a spectrum of resistance levels among genetically identical cells, revealing phenotypic heterogeneity within isogenic populations. This discovery not only advances clinical diagnostics and treatment strategies but also significantly contributes to the field of antibiotic stewardship, underlining the importance of our approach in addressing bacterial resistance.</p>","PeriodicalId":85,"journal":{"name":"Lab on a Chip","volume":" 24","pages":" 5274-5289"},"PeriodicalIF":6.1,"publicationDate":"2024-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142276033","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Label-free high-throughput impedance-activated cell sorting†","authors":"Kui Zhang, Ziyang Xia, Yiming Wang, Lisheng Zheng, Baoqing Li and Jiaru Chu","doi":"10.1039/D4LC00487F","DOIUrl":"10.1039/D4LC00487F","url":null,"abstract":"<p >Cell sorting holds broad applications in fields such as early cancer diagnosis, cell differentiation studies, drug screening, and single-cell sequencing. However, achieving high-throughput and high-purity in label-free single-cell sorting is challenging. To overcome this issue, we propose a label-free, high-throughput, and high-accuracy impedance-activated cell sorting system based on impedance detection and dual membrane pumps. Leveraging the low-latency characteristics of FPGA, the system facilitates real-time dual-frequency single-cell impedance detection with high-throughput (5 × 10<small>⁴</small> cells per s) for HeLa, MDA-MB-231, and Jurkat cells. Furthermore, the system accomplishes low-latency (less than 0.3 ms), label-free, high-throughput (1000 particles per s) and high-accuracy (almost 99%) single-particle sorting using FPGA-based high-precision sort-timing prediction. In experiments with Jurkat and MDA-MB-231 cells, the system achieved a throughput of up to 1000 cells per s, maintaining a pre-sorting purity of 28.57% and increasing post-sorting purity to 97.09%. These findings indicate that our system holds significant potential for applications in label-free, high-throughput cell sorting.</p>","PeriodicalId":85,"journal":{"name":"Lab on a Chip","volume":" 20","pages":" 4918-4929"},"PeriodicalIF":6.1,"publicationDate":"2024-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142276034","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Efficient numerical modelling of magnetophoresis in millifluidic systems†‡","authors":"Johannes Soika, Tobias Wanninger, Patrick Muschak, Anja Schnell, Sebastian P. Schwaminger, Sonja Berensmeier and Markus Zimmermann","doi":"10.1039/D4LC00595C","DOIUrl":"10.1039/D4LC00595C","url":null,"abstract":"<p >Continuous flow magnetophoresis represents a common technique for actively separating particles within a fluid. For separation systems design, accurately predicting particle behaviour helps to characterise system performance, typically measured by the separation efficiency (SE). While finite element method (FEM) simulations offer high accuracy, they demand extensive computational resources. Alternatively, results can be achieved more quickly with simplified numerical models that use analytical descriptions of fluid flow, magnetic fields, and particle movement. In this research, we model a millifluidic system that separates magnetic particles using magnetophoresis. Therefore, we (1) develop a simple numerical model that can simulate continuous flow magnetophoresis for rectangular channels in two and three dimensions, (2) introduce a novel and simple approach to calculate the SE, and (3) quantify the effects of model assumptions in flow profile and dimensions on SE. Our method for estimating SE considers particle flux variation across the channel's cross-section due to the flow profile. The results are compared to an FEM model developed in COMSOL. The obtained three-dimensional simulation model computes results in seconds, around 180 times faster than the FEM approach, while deviating less than 2% from the FEM results. A comparison of the different two-dimensional and three-dimensional models underscores the significant influence of the flow profile and the SE calculation method on the result. The two dimensional models generally overestimate the SE of up to 15% due to their lower peak flow velocity. However, using a constant flow velocity leads to good agreement for high SE due to the overlap of differences in flow profile and SE calculation.</p>","PeriodicalId":85,"journal":{"name":"Lab on a Chip","volume":" 21","pages":" 5009-5019"},"PeriodicalIF":6.1,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2024/lc/d4lc00595c?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142236770","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A paper-in-polymer-pond (PiPP) hybrid microfluidic microplate for multiplexed ultrasensitive detection of cancer biomarkers†","authors":"Sanjay S. Timilsina and XiuJun Li","doi":"10.1039/D4LC00485J","DOIUrl":"10.1039/D4LC00485J","url":null,"abstract":"<p >Conventional affinity-based colorimetric enzyme-linked immunosorbent assay (ELISA) is one of the most widely used methods for the detection of biomarkers. However, rapid point-of-care (POC) detection of multiple cancer biomarkers by conventional ELISA is limited by long incubation time, large reagent volume, and costly instrumentation along with low sensitivity due to the nature of colorimetric methods. Herein, we have developed a reusable and cost-effective paper-in-polymer-pond (PiPP) hybrid microfluidic microplate for ultrasensitive and high-throughput multiplexed detection of disease biomarkers within an hour without using specialized instruments. A piece of pre-patterned chromatography paper placed in the PMMA polymer pond facilitates rapid protein immobilization to avoid intricate surface modifications of polymer and can be changed with a fresh paper layer to reuse the device. Reagents can be simply delivered from the top PMMA layer to multiple microwells in the middle PMMA layer <em>via</em> flow-through microwells, thereby increasing the efficiency of washing and avoiding repeated manual pipetting or costly robots. Quantitative colorimetric analysis was achieved by calculating the brightness of images scanned by an office scanner or a smartphone camera. Sandwich-type immunoassay was performed in the PiPP hybrid device after the optimization of multiple assay conditions. Limits of detection of 0.32 ng mL<small>⁻¹</small> for carcinoembryonic antigen (CEA) and 0.20 ng mL<small>⁻¹</small> for prostate-specific antigen (PSA) were obtained, which were about 10-fold better than those of commercial ELISA kits. We envisage that this simple but versatile hybrid device can have broad applications in various bioassays in resource-limited settings.</p>","PeriodicalId":85,"journal":{"name":"Lab on a Chip","volume":" 21","pages":" 4962-4973"},"PeriodicalIF":6.1,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142236775","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Integrated microfluidic multiple electrode aggregometry for point-of-care platelet function analysis†","authors":"X. Zhao, V. R. Gopal, F. Lozano-Juan, K. Kolandaivelu, A. Sarkar, D. Wu, J. Su, Q. Cheng, R. Pang and L.-S. Wu","doi":"10.1039/D4LC00469H","DOIUrl":"10.1039/D4LC00469H","url":null,"abstract":"<p >Point-of-care (POC) platelet function analysis can enable timely and precise management of bleeding and clotting in emergency rooms, operation rooms and intensive care units. However, POC platelet testing is currently not commonly performed, due to the complexity of sample preparation and limitations of existing technologies. Here, we report the development of an integrated microfluidic multiple electrode aggregometry (μMEA) sensor which uses multi-frequency impedance measurement of an embedded microelectrode array to perform platelet aggregometry directly from whole blood, sensing and measuring platelet activation in a label-free manner and without requiring any additional sample preparation. Additionally, the sensor incorporates blood flow during the assay to account for physiological flow and shear conditions. We show that the impedance signal from the sensor can be used to accurately detect and quantify platelet aggregation in a label-free manner, which was further validated by simultaneous fluorometric measurement and visualization of platelet aggregation. Further, we optimized the sensitivity and repeatability of the sensor using its frequency response and demonstrated that the sensor could be used to characterize drug dose–response in antiplatelet therapy with a frequency-tunable dynamic range. We also demonstrate that the sensor provides high sensitivity to perform platelet aggregometry under thrombocytopenic or low platelet count conditions. The μMEA sensor could thus enable POC platelet function analysis across several clinical applications.</p>","PeriodicalId":85,"journal":{"name":"Lab on a Chip","volume":" 20","pages":" 4859-4868"},"PeriodicalIF":6.1,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142236743","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Reversible bonding in thermoplastic elastomer microfluidic platforms for harvestable 3D microvessel networks†","authors":"Byeong-Ui Moon, Kebin Li, Lidija Malic, Keith Morton, Han Shao, Lauren Banh, Sowmya Viswanathan, Edmond W. K. Young and Teodor Veres","doi":"10.1039/D4LC00530A","DOIUrl":"10.1039/D4LC00530A","url":null,"abstract":"<p >Transplantable ready-made microvessels have therapeutic potential for tissue regeneration and cell replacement therapy. Inspired by the natural rapid angiogenic sprouting of microvessels <em>in vivo</em>, engineered injectable 3D microvessel networks are created using thermoplastic elastomer (TPE) microfluidic devices. The TPE material used here is flexible, optically transparent, and can be robustly yet reversibly bonded to a variety of plastic substrates, making it a versatile choice for microfluidic device fabrication because it overcomes the weak self-adhesion properties and limited manufacturing options of poly(dimethylsiloxane) (PDMS). By leveraging the reversible bonding characteristics of TPE material templates, we present their utility as an organ-on-a-chip platform for forming and handling microvessel networks, and demonstrate their potential for animal-free tissue generation and transplantation in clinical applications. We first show that TPE-based devices have nearly 6-fold higher bonding strength during the cell culture step compared to PDMS-based devices while simultaneously maintaining a full reversible bond to (PS) culture plates, which are widely used for biological cell studies. We also demonstrate the successful generation of perfusable and interconnected 3D microvessel networks using TPE–PS microfluidic devices on both single and multi-vessel loading platforms. Importantly, after removing the TPE slab, microvessel networks remain intact on the PS substrate without any structural damage and can be effectively harvested following gel digestion. The TPE-based organ-on-a-chip platform offers substantial advantages by facilitating the harvesting procedure and maintaining the integrity of microfluidic-engineered microvessels for transplant. To the best of our knowledge, our TPE-based reversible bonding approach marks the first confirmation of successful retrieval of organ-specific vessel segments from the reversibly-bonded TPE microfluidic platform. We anticipate that the method will find applications in organ-on-a-chip and microphysiological system research, particularly in tissue analysis and vessel engraftment, where flexible and reversible bonding can be utilized.</p>","PeriodicalId":85,"journal":{"name":"Lab on a Chip","volume":" 21","pages":" 4948-4961"},"PeriodicalIF":6.1,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2024/lc/d4lc00530a?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142236824","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"SlipO2Chip – single-cell respiration under tuneable environments†","authors":"Yuan Cui, Milena De Albuquerque Moreira, Kristen E. Whalen, Laurent Barbe, Qian Shi, Klaus Koren, Maria Tenje and Lars Behrendt","doi":"10.1039/D4LC00420E","DOIUrl":"10.1039/D4LC00420E","url":null,"abstract":"<p >In disciplines like toxicology and pharmacology, oxygen (O<small>₂</small>) respiration is a universal metric for evaluating the effects of chemicals across various model systems, including mammalian and microalgal cells. However, for these cells the common practice is to segregate populations into control and exposure groups, which assumes direct equivalence in their responses and does not take into account heterogeneity among individual cells. This lack of resolution impedes our ability to precisely investigate differences among experimental groups with small or limited sample sizes. To overcome this barrier, we introduce SlipO<small>₂</small>Chip, an innovative glass microfluidic platform for precisely quantifying single-cell O<small>₂</small> respiration in the coordinated absence and presence of chemical solutes. SlipO<small>₂</small>Chip comprises a wet-etched fused silica channel plate on the top and a dry-etched borosilicate microwell plate at the bottom. The microwells are coated with Pt(<small>II</small>) <em>meso</em>-tetra(pentafluorophenyl)porphine (PtTFPP), an O<small>₂</small> sensing optode material and an O<small>₂</small>-independent reference dye. A custom 3D-printed holder facilitates the controlled horizontal movement (‘slipping’) of the channel plate over the microwell plate, thereby establishing or disrupting the fluid path over microwells. Collectively, these design elements enable the immobilization of single-cells in microwells, their exposure to controlled fluid flows, the coordinated opening and closing of microwells and repeated measurements of single-cell O<small>₂</small> respiration. Uniquely, by sequentially executing opening and closing it becomes possible to measure single-cell respiration prior to and after exposure to chemical solutes. In a proof-of-concept application, we utilized SlipO<small>₂</small>Chip to measure the impact of increasing exposures of the marine bacterial signal 2-heptyl-4-quinolone (HHQ) on the dark respiration of the diatom <em>Ditylum brightwellii</em> at single-cell resolution. Results revealed a concentration-dependent decrease in per-cell O<small>₂</small> dark respiration, with a maximum reduction of 40.2% observed at HHQ concentrations exceeding 35.5 μM, and a half-maximal effective concentration (<em>EC</em><small>₅₀</small>) of 5.8 μM, consistent with that obtained <em>via</em> conventional bulk respiration methods. The ability of SlipO<small>₂</small>Chip to sequentially assess the effects of chemical substances on single-cell O<small>₂</small> metabolism is advantageous for research where sample volumes are limited, such as clinical biopsies, studies involving rare microbial isolates, and toxicological studies aiming to address exposure effects while accounting for cell-to-cell variability.</p>","PeriodicalId":85,"journal":{"name":"Lab on a Chip","volume":" 20","pages":" 4786-4797"},"PeriodicalIF":6.1,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2024/lc/d4lc00420e?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142236771","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}