| 1. |
- Fritzsche, Joachim, 1977, et al.
(författare)
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A lipid-based passivation scheme for nanofluidics
- 2012
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Ingår i: 16th International Conference on Miniaturized Systems for Chemistry and Life Sciences, MicroTAS 2012; Okinawa; Japan; 28 October 2012 through 1 November 2012. - 9780979806452 ; , s. 1876-1878
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Konferensbidrag (refereegranskat)abstract
- Stretching DNA in nanochannels allows for direct, visual studies of genomic DNA at the single molecule level. In order to facilitate the study of the interaction of linear DNA with proteins in nanochannels, we have implemented a highly effective passivation scheme based on lipid bilayers. We show long-term passivation of nanochannel surfaces to several relevant reagents and demonstrate that the performance of the lipid bilayer is significantly better compared to standard bovine serum albumin-based passivation. Moreover, we demonstrate how the passivated devices allow us to monitor single DNA cleavage events during enzymatic degradation.
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| 2. |
- Salm, E., et al.
(författare)
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Integrated 'lab-on-a-transistor' : With droplets-in-air for parallel nanoliter reactions
- 2012
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Ingår i: Proceedings of the 16th International Conference on Miniaturized Systems for Chemistry and Life Sciences, MicroTAS 2012. - : Chemical and Biological Microsystems Society. - 9780979806452 ; , s. 1945-1947
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Konferensbidrag (refereegranskat)abstract
- We aim to take 'lab-on-chip' technology further by introducing the concept of a 'lab-on-transistor'. In this methodology, laboratory operations, such as heating, cell lysis, and detection, are performed on a single transistor instead of on an entire microchip. To demonstrate this concept, we developed a heating technique that allows transistors to act as electrically addressable, individual heating units. We have coupled the transistor heaters with placement of sub-nanoliter droplets to create individual heated reaction volumes. Under this configuration transistors become highly localized heater/sensors capable of high-speed thermocycling (>25°C/s) of <1nL reactions with potential for electrical detection of biological analytes.
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| 3. |
- Christakou, Athanasia E., et al.
(författare)
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Characterization of natural killer cells' cytotoxic heterogeneity using an array of sono-cages
- 2012
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Ingår i: Proceedings of the 16th International Conference on Miniaturized Systems for Chemistry and Life Sciences, MicroTAS 2012. - : Chemical and Biological Microsystems Society. - 9780979806452 ; , s. 1555-1557
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Konferensbidrag (refereegranskat)abstract
- Using a multi-well device as an array of sono-cages for single cell analysis, we quantify for the first time the heterogeneity of natural killer (NK) cells' cytotoxic response against cancer cells. We report a fraction of inactive NK cells within the tested population (36%), as well as the existence of few 'serial killers' that eliminate up to six targets during 4 hours. We also characterize the multi-well acoustic device in terms of trapping efficiency at different actuation voltages, using adherent and non-adherent cell lines. We show that the acoustic forces applied on the cells can be compared to forces of biological processes (i.e. cell adherence).
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| 4. |
- Sjöström, Staffan L., et al.
(författare)
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Multiplex analysis of enzyme kinetics and inhibition by droplet microfluidics using picoinjectors
- 2012
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Ingår i: Proceedings of the 16th International Conference on Miniaturized Systems for Chemistry and Life Sciences, MicroTAS 2012. - 9780979806452 ; , s. 172-174
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Konferensbidrag (refereegranskat)abstract
- We present a novel microdroplet-based device for extensive characterization of the reaction kinetics of enzymeinhibitor systems in a single experiment, for the first time utilizing droplet picoinjectors for bioanalysis. This device enables the scanning of multiple inhibitors, inhibitor concentrations and substrate conditions in a single, highly time resolved experiment yielding the Michaelis constant (Km), the turnover number (Kcat) the mode of inhibition and the inhibitor enzyme binding constants (Ki, Ki). Using this device we determine Km and Kcat for β-galactosidase and the fluorogenic substrate Resorufin β-D-galactopyranoside (RBG) to 252 μM and 477 s-1, respectively. Furthermore, we examine the inhibitory effects of Phenylethyl β-D-thiogalactopyranoside (PETG) on this system.
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| 5. |
- Weibull, Emilie, et al.
(författare)
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Development of a microfluidic concentration gradient generator on a microwell slide for high-throughput cell analysis
- 2012
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Ingår i: Proceedings of the 16th International Conference on Miniaturized Systems for Chemistry and Life Sciences, MicroTAS 2012. - : Chemical and Biological Microsystems Society. - 9780979806452 ; , s. 1573-1575
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Konferensbidrag (refereegranskat)abstract
- The present study reports a newly developed, microfluidic concentration gradient generator that adds substantial utility to the high-throughput nature of the microwell slide that we have previously established [1, 2]. Using microfluidic dynamics, we have designed microchannels to deliver a reagent and its dilutant with precisely controlled flow volumes, generating 8 discrete steps of reagent concentration in designated microwells. As proof of concept FITC-labeled dextran and dextran-free water was used to visualize the concentration gradient. The next step will be to perform cancer drug concentration gradient experiments on an animal cell line.
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| 6. |
- Ohlin, Mathias, et al.
(författare)
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Analysis of trapping and streaming in an ultrasoundactuated multi-well microplate for single-cell studies
- 2012
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Ingår i: Proceedings of the 16th International Conference on Miniaturized Systems for Chemistry and Life Sciences, MicroTAS 2012. - : Chemical and Biological Microsystems Society. - 9780979806452 ; , s. 497-499
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Konferensbidrag (refereegranskat)abstract
- The dynamics of the acoustic streaming and the acoustic positioning performance in an ultrasound-actuated multiwell microplate are investigated by two different ultrasonic frequency actuation schemes: Frequency-modulation and single- frequency actuation. Our results show a significant decrease in size of the field of view when using frequencymodulation compared to single-frequency actuation, which can be used for improving the scanning time for 3D highresolution confocal microscopy by almost one order of magnitude. Furthermore, in the ultrasound-actuated multi-well microplate the high-voltage acoustic streaming show a complex time and temperature dependence and could gain stability by the use of temperature control.
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