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Microfluidic-based blood immunoassays. J Pharm Biomed Anal 2023; 228:115313. [PMID: 36868029 DOI: 10.1016/j.jpba.2023.115313] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Revised: 02/09/2023] [Accepted: 02/22/2023] [Indexed: 02/26/2023]
Abstract
Microfluidics enables the integration of whole protocols performed in a laboratory, including sample loading, reaction, extraction, and measurement steps on a single system, which offers significant advantages thanks to small-scale operation combined with precise fluid control. These include providing efficient transportation mechanisms and immobilization, reduced sample and reagent volumes, fast analysis and response times, lower power requirements, lower cost and disposability, improved portability and sensitivity, and greater integration and automation capability. Immunoassay is a specific bioanalytical method based on the interaction of antigens and antibodies, which is utilized to detect bacteria, viruses, proteins, and small molecules in several areas such as biopharmaceutical analysis, environmental analysis, food safety, and clinical diagnostics. Because of the advantages of both techniques, the combination of immunoassays and microfluidic technology is considered one of the most potential biosensor systems for blood samples. This review presents the current progress and important developments in microfluidic-based blood immunoassays. After providing several basic information about blood analysis, immunoassays, and microfluidics, the review points out in-depth information about microfluidic platforms, detection techniques, and commercial microfluidic blood immunoassay platforms. In conclusion, some thoughts and future perspectives are provided.
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2
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Kosker FB, Aydin O, Icoz K. Simple Staining of Cells on a Chip. BIOSENSORS 2022; 12:1013. [PMID: 36421132 PMCID: PMC9688635 DOI: 10.3390/bios12111013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/10/2022] [Revised: 11/10/2022] [Accepted: 11/11/2022] [Indexed: 06/16/2023]
Abstract
Simple staining of cells is a widely used method in basic medical diagnostics, education, and research laboratories. The stains are low-cost, but the extensive consumption results in excessive toxic waste generation. Thus, to decrease the amount of toxic waste resulting from the cell staining procedure is a need. In this study, we developed a magnetically driven and compartmentalized passive microfluidic chip to perform simple staining of human eukaryotic cells, K562 cells, and lymphocyte cells derived from patients. We demonstrated simple staining on cells with trypan blue, methylene blue, crystal violet, and safranin for high, medium, and low cell densities. The stained cells were imaged using a bright field optical microscope and a cell phone to count cells on the focal plane. The staining improved the color signal of the cell by 25-135-pixel intensity changes for the microscopic images. The validity of the protocol was determined using Jurkat and MDA-MB-231 cell lines as negative controls. In order to demonstrate the practicality of the system, lymphocyte cells derived from human blood samples were stained with trypan blue. The color intensity changes in the first and last compartments were analyzed to evaluate the performance of the chip. The developed method is ultra-low cost, significantly reduces the waste generated, and can be integrated with mobile imaging devices in terms of portability. By combining microfabrication technology with cell staining, this study reported a novel contribution to the field of microfluidic biosensors. In the future, we expect to demonstrate the detection of pathogens using this method.
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Affiliation(s)
- Fatma Betul Kosker
- Department of Biomedical Engineering, Erciyes University, 38039 Kayseri, Türkiye
- Nanothera Lab, Drug Application and Research Center (ERFARMA), Erciyes University, 38039 Kayseri, Türkiye
- Department of Biomedical Engineering, Pamukkale University, 20160 Denizli, Türkiye
| | - Omer Aydin
- Department of Biomedical Engineering, Erciyes University, 38039 Kayseri, Türkiye
- Nanothera Lab, Drug Application and Research Center (ERFARMA), Erciyes University, 38039 Kayseri, Türkiye
- Clinical Engineering Research and Implementation Center (ERKAM), Erciyes University, 38030 Kayseri, Türkiye
- Nanotechnology Research and Application Center (ERNAM), Erciyes University, 38039 Kayseri, Türkiye
| | - Kutay Icoz
- Department of Electrical and Electronics Engineering, Abdullah Gül University, 38080 Kayseri, Türkiye
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Dogan Ü, Sucularlı F, Yildirim E, Cetin D, Suludere Z, Boyaci IH, Tamer U. Escherichia coli Enumeration in a Capillary-Driven Microfluidic Chip with SERS. BIOSENSORS 2022; 12:765. [PMID: 36140150 PMCID: PMC9497094 DOI: 10.3390/bios12090765] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 09/12/2022] [Accepted: 09/14/2022] [Indexed: 11/16/2022]
Abstract
Pathogen detection is still a challenging issue for public health, especially in food products. A selective preconcentration step is also necessary if the target pathogen concentration is very low or if the sample volume is limited in the analysis. Plate counting (24-48 h) methods should be replaced by novel biosensor systems as an alternative reliable pathogen detection technique. The usage of a capillary-driven microfluidic chip is an alternative method for pathogen detection, with the combination of surface-enhanced Raman scattering (SERS) measurements. Here, we constructed microchambers with capillary microchannels to provide nanoparticle-pathogen transportation from one chamber to the other. Escherichia coli (E. coli) was selected as a model pathogen and specific antibody-modified magnetic nanoparticles (MNPs) as a capture probe in a complex milk matrix. MNPs that captured E. coli were transferred in a capillary-driven microfluidic chip consisting of four chambers, and 4-aminothiophenol (4-ATP)-labelled gold nanorods (Au NRs) were used as the Raman probe in the capillary-driven microfluidic chip. The MNPs provided immunomagnetic (IMS) separation and preconcentration of analytes from the sample matrix and then, 4-ATP-labelled Au NRs provided an SERS response by forming sandwich immunoassay structures in the last chamber of the capillary-driven microfluidic chip. The developed SERS-based method could detect 101-107 cfu/mL of E. coli with the total analysis time of less than 60 min. Selectivity of the developed method was also tested by using Salmonella enteritidis (S. enteritidis) and Staphylococcus aureus (S. aureus) as analytes, and very weak signals were observed.
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Affiliation(s)
- Üzeyir Dogan
- Department of Analytical Chemistry, Faculty of Pharmacy, Düzce University, 81620 Düzce, Türkiye
- Department of Analytical Chemistry, Faculty of Pharmacy, Gazi University, Etiler, 06330 Ankara, Türkiye
| | - Ferah Sucularlı
- Aselsan A.Ş., Radar, Electronic Warfare Systems Business Sector, 06172 Ankara, Türkiye
| | - Ender Yildirim
- Department of Mechanical Engineering, Faculty of Engineering, Middle East Technical University, Çankaya, 06800 Ankara, Türkiye
| | - Demet Cetin
- Department of Mathematics and Science Education, Gazi Faculty of Education, Gazi University, Besevler, 06500 Ankara, Türkiye
| | - Zekiye Suludere
- Department of Biology, Faculty of Science, Gazi University, Besevler, 06500 Ankara, Türkiye
| | - Ismail Hakkı Boyaci
- Department of Food Engineering, Hacettepe University, Beytepe, 06800 Ankara, Türkiye
| | - Ugur Tamer
- Department of Analytical Chemistry, Faculty of Pharmacy, Gazi University, Etiler, 06330 Ankara, Türkiye
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Songca SP. Applications of Nanozymology in the Detection and Identification of Viral, Bacterial and Fungal Pathogens. Int J Mol Sci 2022; 23:4638. [PMID: 35563029 PMCID: PMC9100627 DOI: 10.3390/ijms23094638] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2022] [Revised: 02/12/2022] [Accepted: 02/21/2022] [Indexed: 02/05/2023] Open
Abstract
Nanozymes are synthetic nanoparticulate materials that mimic the biological activities of enzymes by virtue of their surface chemistry. Enzymes catalyze biological reactions with a very high degree of specificity. Examples include the horseradish peroxidase, lactate, glucose, and cholesterol oxidases. For this reason, many industrial uses of enzymes outside their natural environments have been developed. Similar to enzymes, many industrial applications of nanozymes have been developed and used. Unlike the enzymes, however, nanozymes are cost-effectively prepared, purified, stored, and reproducibly and repeatedly used for long periods of time. The detection and identification of pathogens is among some of the reported applications of nanozymes. Three of the methodologic milestones in the evolution of pathogen detection and identification include the incubation and growth, immunoassays and the polymerase chain reaction (PCR) strategies. Although advances in the history of pathogen detection and identification have given rise to novel methods and devices, these are still short of the response speed, accuracy and cost required for point-of-care use. Debuting recently, nanozymology offers significant improvements in the six methodological indicators that are proposed as being key in this review, including simplicity, sensitivity, speed of response, cost, reliability, and durability of the immunoassays and PCR strategies. This review will focus on the applications of nanozymes in the detection and identification of pathogens in samples obtained from foods, natural, and clinical sources. It will highlight the impact of nanozymes in the enzyme-linked immunosorbent and PCR strategies by discussing the mechanistic improvements and the role of the design and architecture of the nanozyme nanoconjugates. Because of their contribution to world health burden, the three most important pathogens that will be considered include viruses, bacteria and fungi. Although not quite seen as pathogens, the review will also consider the detection of cancer cells and helminth parasites. The review leaves very little doubt that nanozymology has introduced remarkable advances in enzyme-linked immunosorbent assays and PCR strategies for detecting these five classes of pathogens. However, a gap still exists in the application of nanozymes to detect and identify fungal pathogens directly, although indirect strategies in which nanozymes are used have been reported. From a mechanistic point of view, the nanozyme technology transfer to laboratory research methods in PCR and enzyme-linked immunosorbent assay studies, and the point-of-care devices such as electronic biosensors and lateral flow detection strips, that is currently taking place, is most likely to give rise to no small revolution in each of the six methodological indicators for pathogen detection and identification. While the evidence of widespread research reports, clinical trials and point-of-care device patents support this view, the gaps that still exist point to a need for more basic research studies to be conducted on the applications of nanozymology in pathogen detection and identification. The multidisciplinary nature of the research on the application of nanozymes in the detection and identification of pathogens requires chemists and physicists for the design, fabrication, and characterization of nanozymes; microbiologists for the design, testing and analysis of the methodologies, and clinicians or clinical researchers for the evaluation of the methodologies and devices in the clinic. Many reports have also implicated required skills in mathematical modelling, and electronic engineering. While the review will conclude with a synopsis of the impact of nanozymology on the detection and identification of viruses, bacteria, fungi, cancer cells, and helminths, it will also point out opportunities that exist in basic research as well as opportunities for innovation aimed at novel laboratory methodologies and devices. In this regard there is no doubt that there are numerous unexplored research areas in the application of nanozymes for the detection of pathogens. For example, most research on the applications of nanozymes for the detection and identification of fungi is so far limited only to the detection of mycotoxins and other chemical compounds associated with fungal infection. Therefore, there is scope for exploration of the application of nanozymes in the direct detection of fungi in foods, especially in the agricultural production thereof. Many fungal species found in seeds severely compromise their use by inactivating the germination thereof. Fungi also produce mycotoxins that can severely compromise the health of humans if consumed.
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Affiliation(s)
- Sandile Phinda Songca
- School of Chemistry and Physics, College of Agriculture Engineering and Science, University of KwaZulu-Natal, Durban 4041, South Africa
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5
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Continuous Microfluidic Purification of DNA Using Magnetophoresis. MICROMACHINES 2020; 11:mi11020187. [PMID: 32054004 PMCID: PMC7074667 DOI: 10.3390/mi11020187] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Revised: 02/05/2020] [Accepted: 02/07/2020] [Indexed: 12/13/2022]
Abstract
Automatic microfluidic purification of nucleic acid is predictable to reduce the input of original samples and improve the throughput of library preparation for sequencing. Here, we propose a novel microfluidic system using an external NdFeB magnet to isolate DNA from the polymerase chain reaction (PCR) mixture. The DNA was purified and isolated when the DNA-carrying beads transported to the interface of multi-laminar flow under the influence of magnetic field. Prior to the DNA recovery experiments, COMSOL simulations were carried out to study the relationship between trajectory of beads and magnet positions as well as fluid velocities. Afterwards, the experiments to study the influence of varying velocities and input of samples on the DNA recovery were conducted. Compared to experimental results, the relative error of the final position of beads is less than 10%. The recovery efficiency decreases with increase of input or fluid velocity, and the maximum DNA recovery efficiency is 98.4% with input of l00 ng DNA at fluid velocity of 1.373 mm/s. The results show that simulations significantly reduce the time for parameter adjustment in experiments. In addition, this platform uses a basic two-layer chip to realize automatic DNA isolation without any other liquid switch value or magnet controller.
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Fast fluorometric enumeration of E. coli using passive chip. J Microbiol Methods 2019; 164:105680. [DOI: 10.1016/j.mimet.2019.105680] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Revised: 07/31/2019] [Accepted: 08/01/2019] [Indexed: 01/06/2023]
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Gädke J, Thies JW, Kleinfeldt L, Schulze T, Biedendieck R, Rustenbeck I, Garnweitner G, Krull R, Dietzel A. Selective manipulation of superparamagnetic nanoparticles for product purification and microfluidic diagnostics. Eur J Pharm Biopharm 2018; 126:67-74. [DOI: 10.1016/j.ejpb.2017.09.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2016] [Revised: 08/02/2017] [Accepted: 09/12/2017] [Indexed: 01/20/2023]
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8
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Liu C, Cai H, Jia J, Cao T, Xu C, Liu C. Research on highly sensitive optomagnetic sensor for rapid detection of inflammation. Technol Health Care 2017; 25:151-156. [DOI: 10.3233/thc-171317] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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9
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Mosley O, Melling L, Tarn MD, Kemp C, Esfahani MMN, Pamme N, Shaw KJ. Sample introduction interface for on-chip nucleic acid-based analysis of Helicobacter pylori from stool samples. LAB ON A CHIP 2016; 16:2108-15. [PMID: 27164181 DOI: 10.1039/c6lc00228e] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
Despite recent advances in microfluidic-based integrated diagnostic systems, the sample introduction interface, especially with regards to large volume samples, has often been neglected. We present a sample introduction interface that allows direct on-chip processing of crude stool samples for the detection of Helicobacter pylori (H. pylori). The principle of IFAST (immiscible filtration assisted by surface tension) was adapted to include a large volume sample chamber with a septum-based interface for stool sample introduction. Solid chaotropic salt and dry superparamagnetic particles (PMPs) could be stored on-chip and reconstituted upon sample addition, simplifying the process of release of DNA from H. pylori cells and its binding to the PMPs. Finally, the PMPs were pulled via a magnet through a washing chamber containing an immiscible oil solution and into an elution chamber where the DNA was released into aqueous media for subsequent analysis. The entire process required only 7 min while enabling a 40-fold reduction in working volume from crude biological samples. The combination of a real-world interface and rapid DNA extraction offers the potential for the methodology to be used in point-of-care (POC) devices.
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Affiliation(s)
- O Mosley
- Faculty of Science and Engineering, Manchester Metropolitan University, Chester Street, Manchester, M1 5GD, UK.
| | - L Melling
- Faculty of Science and Engineering, Manchester Metropolitan University, Chester Street, Manchester, M1 5GD, UK.
| | - M D Tarn
- Department of Chemistry, University of Hull, Cottingham Road, Hull, HU6 7RX, UK.
| | - C Kemp
- Department of Chemistry, University of Hull, Cottingham Road, Hull, HU6 7RX, UK.
| | - M M N Esfahani
- School of Engineering, University of Hull, Cottingham Road, Hull, HU6 7RX, UK
| | - N Pamme
- Department of Chemistry, University of Hull, Cottingham Road, Hull, HU6 7RX, UK.
| | - K J Shaw
- Faculty of Science and Engineering, Manchester Metropolitan University, Chester Street, Manchester, M1 5GD, UK.
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10
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Bioanalytical advances in assays for C-reactive protein. Biotechnol Adv 2016; 34:272-90. [DOI: 10.1016/j.biotechadv.2015.12.010] [Citation(s) in RCA: 94] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2015] [Revised: 12/17/2015] [Accepted: 12/18/2015] [Indexed: 01/08/2023]
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11
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Phurimsak C, Tarn MD, Pamme N. Magnetic Particle Plug-Based Assays for Biomarker Analysis. MICROMACHINES 2016; 7:E77. [PMID: 30404252 PMCID: PMC6190463 DOI: 10.3390/mi7050077] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/13/2016] [Revised: 04/01/2016] [Accepted: 04/13/2016] [Indexed: 01/08/2023]
Abstract
Conventional immunoassays offer selective and quantitative detection of a number of biomarkers, but are laborious and time-consuming. Magnetic particle-based assays allow easy and rapid selection of analytes, but still suffer from the requirement of tedious multiple reaction and washing steps. Here, we demonstrate the trapping of functionalised magnetic particles within a microchannel for performing rapid immunoassays by flushing consecutive reagent and washing solutions over the trapped particle plug. Three main studies were performed to investigate the potential of the platform for quantitative analysis of biomarkers: (i) a streptavidin-biotin binding assay; (ii) a sandwich assay of the inflammation biomarker, C-reactive protein (CRP); and (iii) detection of the steroid hormone, progesterone (P4), towards a competitive assay. Quantitative analysis with low limits of detection was demonstrated with streptavidin-biotin, while the CRP and P4 assays exhibited the ability to detect clinically relevant analytes, and all assays were completed in only 15 min. These preliminary results show the great potential of the platform for performing rapid, low volume magnetic particle plug-based assays of a range of clinical biomarkers via an exceedingly simple technique.
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Affiliation(s)
- Chayakom Phurimsak
- Department of Chemistry, University of Hull, Cottingham Road, Hull, HU6 7RX, UK.
| | - Mark D Tarn
- Department of Chemistry, University of Hull, Cottingham Road, Hull, HU6 7RX, UK.
| | - Nicole Pamme
- Department of Chemistry, University of Hull, Cottingham Road, Hull, HU6 7RX, UK.
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Leng Y, Sun K, Chen X, Li W. Suspension arrays based on nanoparticle-encoded microspheres for high-throughput multiplexed detection. Chem Soc Rev 2015; 44:5552-95. [PMID: 26021602 PMCID: PMC5223091 DOI: 10.1039/c4cs00382a] [Citation(s) in RCA: 163] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Spectrometrically or optically encoded microsphere based suspension array technology (SAT) is applicable to the high-throughput, simultaneous detection of multiple analytes within a small, single sample volume. Thanks to the rapid development of nanotechnology, tremendous progress has been made in the multiplexed detecting capability, sensitivity, and photostability of suspension arrays. In this review, we first focus on the current stock of nanoparticle-based barcodes as well as the manufacturing technologies required for their production. We then move on to discuss all existing barcode-based bioanalysis patterns, including the various labels used in suspension arrays, label-free platforms, signal amplification methods, and fluorescence resonance energy transfer (FRET)-based platforms. We then introduce automatic platforms for suspension arrays that use superparamagnetic nanoparticle-based microspheres. Finally, we summarize the current challenges and their proposed solutions, which are centered on improving encoding capacities, alternative probe possibilities, nonspecificity suppression, directional immobilization, and "point of care" platforms. Throughout this review, we aim to provide a comprehensive guide for the design of suspension arrays, with the goal of improving their performance in areas such as multiplexing capacity, throughput, sensitivity, and cost effectiveness. We hope that our summary on the state-of-the-art development of these arrays, our commentary on future challenges, and some proposed avenues for further advances will help drive the development of suspension array technology and its related fields.
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Affiliation(s)
- Yuankui Leng
- The State Key Lab of Metal Matrix Composites, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China.
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Young JE, Posada D, Lopez JM, Hirsa AH. Flow-induced 2D protein crystallization: characterization of the coupled interfacial and bulk flows. SOFT MATTER 2015; 11:3618-3628. [PMID: 25805062 DOI: 10.1039/c5sm00429b] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Two-dimensional crystallization of the protein streptavidin, crystallizing below a biotinylated lipid film spread on a quiescent air-water interface is a well studied phenomenon. More recently, 2D crystallization induced by a shearing interfacial flow has been observed at film surface pressures significantly lower than those required in a quiescent system. Here, we quantify the interfacial and bulk flow associated with 2D protein crystallization through numerical modeling of the flow along with a Newtonian surface model. Experiments were conducted over a wide range of conditions resulting in a state diagram delineating the flow strength required to induce crystals for various surface pressures. Through measurements of the velocity profile at the air-water interface, we found that even in the cases where crystals are formed, the macroscopic flow at the interface is well described by the Newtonian model. However, the results show that even in the absence of any protein in the system, the viscous response of the biotinylated lipid film is complicated and strongly dependent on the strength of the flow. This observation suggests that the insoluble lipid film plays a key role in flow-induced 2D protein crystallization.
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Affiliation(s)
- James E Young
- Department of Mechanical, Aerospace and Nuclear Engineering, Rensselaer Polytechnic Institute, Troy, NY 12180-3590, USA.
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14
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Ng AHC, Lee M, Choi K, Fischer AT, Robinson JM, Wheeler AR. Digital microfluidic platform for the detection of rubella infection and immunity: a proof of concept. Clin Chem 2014; 61:420-9. [PMID: 25512641 DOI: 10.1373/clinchem.2014.232181] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
BACKGROUND Whereas disease surveillance for infectious diseases such as rubella is important, it is critical to identify pregnant women at risk of passing rubella to their offspring, which can be fatal and can result in congenital rubella syndrome (CRS). The traditional centralized model for diagnosing rubella is cost-prohibitive in resource-limited settings, representing a major obstacle to the prevention of CRS. As a step toward decentralized diagnostic systems, we developed a proof-of-concept digital microfluidic (DMF) diagnostic platform that possesses the flexibility and performance of automated immunoassay platforms used in central facilities, but with a form factor the size of a shoebox. METHODS DMF immunoassays were developed with integrated sample preparation for the detection of rubella virus (RV) IgG and IgM. The performance (sensitivity and specificity) of the assays was evaluated with serum and plasma samples from a commercial antirubella mixed-titer performance panel. RESULTS The new platform performed the essential processing steps, including sample aliquoting for 4 parallel assays, sample dilution, and IgG blocking. Testing of performance panel samples yielded diagnostic sensitivity and specificity of 100% and 100% for both RV IgG and RV IgM. With 1.8 μL sample per assay, 4 parallel assays were performed in approximately 30 min with <10% mean CV. CONCLUSIONS This proof of concept establishes DMF-powered immunoassays as being potentially useful for the diagnosis of infectious disease.
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Affiliation(s)
- Alphonsus H C Ng
- Institute of Biomaterials and Biomedical Engineering, Donnelly Centre for Cellular and Biomolecular Research, Toronto, ON, Canada
| | - Misan Lee
- Innis College, and Donnelly Centre for Cellular and Biomolecular Research, Toronto, ON, Canada
| | - Kihwan Choi
- Donnelly Centre for Cellular and Biomolecular Research, Toronto, ON, Canada; Department of Chemistry, University of Toronto, Toronto, ON, Canada
| | | | | | - Aaron R Wheeler
- Institute of Biomaterials and Biomedical Engineering, Donnelly Centre for Cellular and Biomolecular Research, Toronto, ON, Canada; Department of Chemistry, University of Toronto, Toronto, ON, Canada;
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15
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Yildirim E, Trietsch SJ, Joore J, van den Berg A, Hankemeier T, Vulto P. Phaseguides as tunable passive microvalves for liquid routing in complex microfluidic networks. LAB ON A CHIP 2014; 14:3334-3340. [PMID: 24989781 DOI: 10.1039/c4lc00261j] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
A microfluidic passive valving platform is introduced that has full control over the stability of each valve. The concept is based on phaseguides, which are small ridges at the bottom of a channel acting as pinning barriers. It is shown that the angle between the phaseguide and the channel sidewall is a measure of the stability of the phaseguide. The relationship between the phaseguide-wall angle and the stability is characterized numerically, analytically and experimentally. Liquid routing is enabled by using multiple phaseguide with different stability values. This is demonstrated by filling complex chamber matrices. As an ultimate demonstration of control, a 400-chamber network is used as a pixel array. It is the first time that differential stability is demonstrated in the realm of passive valving. It ultimately enables microfluidic devices for massive data generation in a low-cost disposable format.
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Affiliation(s)
- Ender Yildirim
- Division for Analytical Biosciences, Leiden Academic Centre for Drug Research, University of Leiden, 2300 RA, Leiden, The Netherlands.
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