| 1. |
- Alizadehheidari, Mohammadreza, 1987, et al.
(författare)
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Nanoconfined circular DNA
- 2014
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Ingår i: 18th International Conference on Miniaturized Systems for Chemistry and Life Sciences, MicroTAS 2014. - 9780979806476 ; , s. 1353-1355
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Konferensbidrag (refereegranskat)abstract
- Studies of nanoconfined circular DNA are of interest both from a biological as well as a fundamental polymer physics perspective. We here present the use of nanofluidic channels as a tool for comparing statics and dynamics of the linear and circular configuration of the same DNA molecule.
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| 2. |
- Antfolk, M., et al.
(författare)
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Acoustophoresis for label-free separation and concentration of cancer cells
- 2014
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Ingår i: 18th International Conference on Miniaturized Systems for Chemistry and Life Sciences, MicroTAS 2014. - 9780979806476 ; , s. 2508-2509
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Konferensbidrag (refereegranskat)abstract
- Here, an acoustophoresis chip is presented that is capable of separating cancer cells from white blood cells (WBCs) and subsequently concentrating the recovered cells in the same chip. The chip utilizes ultrasound standing waves in two dimensions to pre-align, separate and concentrate the cells. 92% of the cancer cells could be recovered while keeping the contamination level of WBCs to only 0.6%. The recovered cancer cells were concentrated 24 times.
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| 3. |
- Chinnasamy, Thiruppathiraja, et al.
(författare)
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Towards paper-based point of care affinity proteomics
- 2014
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Ingår i: 18th International Conference on Miniaturized Systems for Chemistry and Life Sciences, MicroTAS 2014. - : Chemical and Biological Microsystems Society. - 9780979806476 ; , s. 64-66
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Konferensbidrag (refereegranskat)abstract
- Affinity-based methods such as protein microarrays have come to complement conventional mass/charge-based techniques for proteomic characterization of biological samples. Simultaneous measurement of hundreds or even thousands of serum biomarkers such as antibodies, antigens and other proteins may greatly improve the diagnostic accuracy in a variety of conditions such as autoimmune disorders, infections and several cancers. However, today's technologies for affinity proteomics are cumbersome, require expensive equipment and skilled operators. Here, we present two novel paper-based techniques developed in our lab that aim to bridge the gap between highly multiplexed affinity proteomics and point of care testing.
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| 4. |
- Christakou, Athanasia E., et al.
(författare)
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Solid tumor spheroid formation by temperature-controlled high voltage ultrasound in a multi-well microdevice
- 2014
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Ingår i: 18th International Conference on Miniaturized Systems for Chemistry and Life Sciences, MicroTAS 2014. - : Chemical and Biological Microsystems SocietyChemical and Biological Microsystems Society. - 9780979806476 ; , s. 573-575
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Konferensbidrag (refereegranskat)abstract
- In the present work we demonstrate effective 3D growth of human hepatocellular carcinoma (HCC) HepG2 cell spheroids in parallel in a multi-well microdevice actuated with high voltage ultrasound in a temperature-controlled system. We compare the spheroid formation during continuous ultrasound exposure for one week where we formed spheroids in 59% of the wells, with the spheroid formation without ultrasound actuation, where we obtained 0% spheroids. Furthermore, we present an application of the tumor spheroids for investigating natural killer (NK) cells behavior against solid tumors.
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| 5. |
- Cushing, Kevin W., et al.
(författare)
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Label-free enrichment of cancer cells using negative selection (depletion) of wbcs with elastomeric negative acoustic contrast particles and acoustophoresis
- 2014
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Ingår i: 18th International Conference on Miniaturized Systems for Chemistry and Life Sciences, MicroTAS 2014. - 9781634396974 - 9780979806476 ; , s. 2540-2541
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Konferensbidrag (refereegranskat)abstract
- In an effort to bioengineer elastomeric particles (EPs), with negative acoustic contrast factor, to capture cells, we have successfully functionalized EPs with anti-human CD45 antibodies that enable capturing of WBCs from human RBC lysed blood samples. We demonstrate that the negative selection of WBCs with EPs and acoustophoresis can be employed to reduce WBC contamination while enriching label-free prostate cancer cells (DU145) within the central fraction of our acoustophoresis chip.
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| 6. |
- Fornander, Louise, 1984, et al.
(författare)
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Using nanofluidic channels to probe dynamics of RAD51-Filaments
- 2015
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Ingår i: 18th International Conference on Miniaturized Systems for Chemistry and Life Sciences, MicroTAS 2014. - 9780979806476 ; , s. 1826-1828
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Konferensbidrag (refereegranskat)abstract
- Using nanochannels, passivated with a lipid bilayer to avoid sticking of proteins, we study Rad51 filaments bound to single- and double stranded DNA. We demonstrate how we can discern different properties of the filaments by studying them at different degrees of confinement. Unlike the bacterial homologue RecA, that forms homogeneous filaments along DNA, Rad51 forms heterogeneous filaments containing both rigid kinks as well as flexible regions. Varying the counterion, the DNA substrate as well as the initial protein concentration, we try to understand the factors governing the structure of the filaments.
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| 7. |
- Hansson, Jonas, 1983-, et al.
(författare)
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Direct Lithography of Rubbery OSTE+ Polymer
- 2014
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Ingår i: Proceedings 18th International Conference on Miniaturized Systems for Chemistry and Life Sciences (MicroTAS2014). - : 14CBMS. - 9780979806476 ; , s. 123-125
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Konferensbidrag (refereegranskat)abstract
- We present a Rubbery, Off-Stoichiometric Thiol-Ene-epoxy (OSTE+) polymer for direct lithography manufacturing, demonstrate its use in pneumatic pinch microvalves for lab-on-chip applications, test the lithography process achieving pillars of aspect-ratios (a.r.) 1:8, and characterize it’s surface as hydrophilic.
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| 8. |
- Holm, Stefan H., et al.
(författare)
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Density-based particle fractionation
- 2014
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Ingår i: 18th International Conference on Miniaturized Systems for Chemistry and Life Sciences, MicroTAS 2014. - 9780979806476 ; , s. 288-290
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Konferensbidrag (refereegranskat)abstract
- We present a label-free method capable of rapidly sorting particles based on their densities. Our device relies on deterministic lateral displacement (DLD) and achieves density fractionation by the use of T-shaped posts. By combining it with a lateral density gradient we achieve a density separation that is independent of size within a range given by the device geometry. Herein we present a proof-of-principle method which, in comparison to traditional density-separation techniques, is suitable for lab-on-a-chip environment.
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| 9. |
- Iranmanesh, I., et al.
(författare)
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On-chip ultrasonic sample preparation for cellular and molecular diagnostics
- 2014
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Ingår i: 18th International Conference on Miniaturized Systems for Chemistry and Life Sciences, MicroTAS 2014. - : Chemical and Biological Microsystems Society. - 9780979806476 ; , s. 1163-1165
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Konferensbidrag (refereegranskat)abstract
- In the present paper we combine for the first time kHz- and MHz-frequency ultrasonic actuation for on-chip size-based isolation, up-concentration and lysis of cells. As proof of concept, we demonstrate MHz-frequency ultrasonic isolation and trapping of ∼10-μm (RH-30) cancer cells from ∼5-μm RBCs, and we investigate the kHz-frequency ultrasonic lysis effect on isolated cancer cells.
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| 10. |
- Lenk, Gabriel Arne, et al.
(författare)
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Delay valving in capillary driven devices based on dissolvable thin films
- 2014
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Ingår i: 18th International Conference on Miniaturized Systems for Chemistry and Life Sciences, MicroTAS 2014. - : Chemical and Biological Microsystems Society. - 9780979806476 ; , s. 216-218
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Konferensbidrag (refereegranskat)abstract
- This work presents passive time delay valves for micro channels in two different working modes for microfluidic on chip timing. The delay valve designs are compatible with conventional lamination techniques for microfluidics and allow to pre-program advanced sequential operations independent from the geometries of the microfluidic system. The time delay of the dissolvable valves ranges from 1.2 s up to 36 s per valve resulting in a time range from 1.2 seconds up to 11 minutes for 19 serial valves.
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| 11. |
- Lenshof, A., et al.
(författare)
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Improved acoustophoretic circulating tumor cell (CTC) separation for low target cell numbers in clinical volumes
- 2014
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Ingår i: 18th International Conference on Miniaturized Systems for Chemistry and Life Sciences, MicroTAS 2014. - 9780979806476 ; , s. 594-596
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Konferensbidrag (refereegranskat)abstract
- We present an improved acoustophoretic system for circulating tumor cell separation from blood. The system is operated by pressure driven flow, including flow sensors and a feed-back loop for precise flow control. The pressure driven system provides a user interface that can be handled by a non-skilled operator, and most importantly full clinical samples of 7 mL can be processed in 70 minutes. The improved flow control enables recovery of rare tumor cell populations ≈10 cells/mL spiked in whole blood at a recovery close to 100%.
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| 12. |
- Nyberg, Lena, 1979, et al.
(författare)
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Optical mapping of single DNA molecules in nanochannels: A novel method for identification and characterization of antibiotic resistance
- 2015
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Ingår i: 18th International Conference on Miniaturized Systems for Chemistry and Life Sciences, MicroTAS 2014. - 9780979806476 ; , s. 1045-1047
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Konferensbidrag (refereegranskat)abstract
- The use, and overuse, of antibiotics has during the last decade led to a dramatic increase in antibiotic resistance and there is a crying need for novel methods for fast identification of antibiotic resistance genes. We here demonstrate how our previously developed assay for optical mapping of DNA in nanochannels can be used for characterization of resistance genes located on plasmid DNA from bacteria. The assay requires extremely small sample volumes and does neither rely on PCR, nor culturing of bacteria, which greatly reduces the time for analysis.
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| 13. |
- Ohlander, A., et al.
(författare)
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Real-time monitoring of melting curves on DNA microarrays in plastic lab-on-foil system using silicon photomultiplier detectors
- 2014
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Ingår i: 18th International Conference on Miniaturized Systems for Chemistry and Life Sciences, MicroTAS 2014. - : Chemical and Biological Microsystems Society. - 9780979806476 ; , s. 2294-2296
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Konferensbidrag (refereegranskat)abstract
- We report on DNA genotyping by melting curve analysis (MCA) in a plastic foil-microfluidic system using silicon photomultiplier (SiPM) detectors. Matching and single base mismatching DNA oligonucleotides were immobilized on thin-film foil microheaters and integrated in microfluidic channels using lamination foils. Two SiPMs, each with a sensitive area of 1.2×1.2 mm were assembled in an optical measurement setup to monitor the decaying Cy3 fluorescence intensity of the hybridized DNA spots upon melting. Successful detection of single nucleotide polymorphisms (SNP) is demonstrated.
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| 14. |
- Ohlsson, Pelle, et al.
(författare)
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Acoustic separation of bacteria from blood cells at high cell concentrations enabled by acoustic impedance matched buffers
- 2014
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Ingår i: 18th International Conference on Miniaturized Systems for Chemistry and Life Sciences, MicroTAS 2014. - 9780979806476 ; , s. 388-390
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Konferensbidrag (refereegranskat)abstract
- We have developed a method to separate bacteria from red and white blood cells (henceforth collectively called blood cells) using acoustophoresis, for subsequent PCR detection. To maximize throughput, we have now investigated the effect of increased cell concentration on the separation. Increasing the blood concentration drastically decreases bacteria recovery, but we show that this can be remedied by optimizing the acoustic impedance of the center buffer. This way we can recover 89% of the bacteria while removing more than 99.8% of the blood cells from 1 ml whole blood within 25 min, paving the way for new sepsis diagnostics methods.
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| 15. |
- Persson, E, et al.
(författare)
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Label-free and non-contact platelet analysis platform
- 2014
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Ingår i: 18th International Conference on Miniaturized Systems for Chemistry and Life Sciences, MicroTAS 2014. - 9780979806476 ; , s. 2542-2543
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Konferensbidrag (refereegranskat)abstract
- We present a non-contact platelet functional analysis platform based on acoustic trapping of platelet clusters and activation monitoring using impedance spectroscopy. The system was characterized using polystyrene particles and human platelets. The system was also capable of transferring platelets from plasma into a controlled buffer. Trapped platelets were activated using 20 and 40 μM TRAP and their responses were recorded with impedance spectroscopy. The system shows great promise as a miniaturized, automatable platform for platelet analysis.
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| 16. |
- Petersson, Klara, et al.
(författare)
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Integrated acoustic sample preparation for rapid sepsis diagnostics
- 2014
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Ingår i: 18th International Conference on Miniaturized Systems for Chemistry and Life Sciences, MicroTAS 2014. - 9781634396974 - 9780979806476 ; , s. 294-296
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Konferensbidrag (refereegranskat)abstract
- We present a novel, integrated microfluidic system based on acoustophoretic cell-handling that detects bacteria in whole blood in less than 2 hours, substantially faster than current standard methods for detection of sepsis-causing bacteria. Bacteria are acoustically separated from 1 ml blood, enriched by acoustic trapping and finally detected using a dry-reagent PCR-chip.
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| 17. |
- Ramachandraiah, Harisha, et al.
(författare)
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In situ isothermal rolling circle amplification (RCA) of DNA and bead based visualization of RCA products on an integrated lab on DVD platform for low cost molecular diagnostics
- 2014
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Ingår i: 18th International Conference on Miniaturized Systems for Chemistry and Life Sciences, MicroTAS 2014. - 9780979806476 ; , s. 1422-1424
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Konferensbidrag (refereegranskat)abstract
- Isothermal rolling circle amplification (RCA) is a simple and versatile isothermal enzymatic nucleic acid amplification techniques, and has been demonstrated as a ideal tool for biomedical research. We demonstrate for the first time the detection of padlock probes mediated and rolling circle amplification of DNA on centrifugal microfluidic system. DNA spotted on DVD substrate is amplified in-situ and novel bead-based detection of the amplified product is demonstrated using a modified commercial DVD reader for "image based" molecular diagnostics.
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| 18. |
- Santiago-Felipe, S., et al.
(författare)
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DVD discs as low-cost diagnostics for GMO screening
- 2014
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Ingår i: 18th International Conference on Miniaturized Systems for Chemistry and Life Sciences, MicroTAS 2014. - : Chemical and Biological Microsystems Society. - 9780979806476 ; , s. 1413-1415
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Konferensbidrag (refereegranskat)abstract
- We demonstrate the incorporation of low-cost and easy-to-fabricate microfluidic chambers on digital versatile discs (DVDs) to perform DNA assays using standard, commercially available and unmodified DVD drives. This simple microarray-based method is applied for the screening of seven prevalent strains of genetically modified organisms (GMOs) in maize and soybean food samples. The detection limit of our system was found to be 7 μg/g, well exceeding the EU regulation limits for GMOs in food products.
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| 19. |
- Sjöström, Staffan, et al.
(författare)
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Micro-droplet based directed evolution outperforms conventional laboratory evolution
- 2014
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Ingår i: 18th International Conference on Miniaturized Systems for Chemistry and Life Sciences, MicroTAS 2014. - : Chemical and Biological Microsystems Society. - 9780979806476 ; , s. 169-171
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Konferensbidrag (refereegranskat)abstract
- We present droplet adaptive laboratory evolution (DrALE), a directed evolution method used to improve industrial enzyme producing microorganisms for e.g. feedstock digestion. DrALE is based linking a desired phenotype to growth rate allowing only desired cells to proliferate. Single cells are confined in microfluidic droplets to prevent the phenotype, e.g. secreted enzymes, from leaking between cells. The method was benchmarked against and found to significantly outperform conventional adaptive laboratory evolution (ALE) in enriching enzyme producing cells. It was furthermore applied to enrich a whole-genome mutated library of yeast cells for α-amylase activity.
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| 20. |
- Tegenfeldt, Jonas O., et al.
(författare)
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Label-free cytometry - Novel sorting parameters and opportunities
- 2014
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Ingår i: 18th International Conference on Miniaturized Systems for Chemistry and Life Sciences, MicroTAS 2014. - 9780979806476 ; , s. 242-245
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Konferensbidrag (refereegranskat)abstract
- The inherent properties of cells and micro-organisms is an under-explored source of specificity for particle sorting. In contrast to standard immunolabeling it allows us to perform fractionation without any chemical preparation of the sample. This improves the accessibility and affordability of the technology. Our contribution in the field is to extend the scope of deterministic lateral displacement (DLD) from merely a very powerful size-based sorting scheme so that it is used to sort with respect to several other physical parameters. We have explored parameters such as shape, deformability, dielectric properties, secretion and density with potential applications in bacteriology, parasitology and oncology.
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| 21. |
- Xia, Y., et al.
(författare)
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Continuous acoustic sorting of E. Coli and G. Lamblia in drinking water
- 2014
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Ingår i: 18th International Conference on Miniaturized Systems for Chemistry and Life Sciences, MicroTAS 2014. - 9780979806476 ; , s. 2456-2458
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Konferensbidrag (refereegranskat)abstract
- This paper presents an acoustofluidic chip for the sorting of bacteria from protozoa in water using standing acoustic waves. The size-based acoustophoretic sorting method provides a means for sample pre-concentration, which is vital for real-time, on-site monitoring of drinking water quality and preventing outbreak of waterborne diseases. In practice, high throughput and high recovery pre-concentration is required for precise microbial detection, because of low sample concentration in drinking water. In this paper, Giardia Lamblia (G. Lamblia) and Escherichia coli (E. coli), the most common protozoon and bacterium in drinking water, are successfully separated with 98% recovery. In addition, the relationship between microbial recovery and sample flow rate is obtained.
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| 22. |
- Zelenin, Sergey, et al.
(författare)
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High density custom microarrays formed by microcompartment amplification on glass surface
- 2014
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Ingår i: 18th International Conference on Miniaturized Systems for Chemistry and Life Sciences, MicroTAS 2014. - : Chemical and Biological Microsystems Society. - 9780979806476 ; , s. 1027-1029
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Konferensbidrag (refereegranskat)abstract
- Compartmentalization of a single DNA molecule is necessary for digital amplification. In the present study we have developed a microscale isothermal amplification using exponential rolling circle amplification (RCA). RCA was performed in PDMS microcompartments on a microarray glass, with a volume of less than 1 pL. Resulting amplicons were attached to the glass surface and formed a custom array with the density of spots above 2,5 × 105 per cm2. Our technology can be applied for digital amplification of DNA or RNA from a variety of complex biological samples in a microchip format.
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