| 1. |
- Aleklett, Kristin, et al.
(författare)
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Build your own soil : exploring microfluidics to create microbial habitat structures
- 2018
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Ingår i: ISME Journal. - : Springer Science and Business Media LLC. - 1751-7362 .- 1751-7370. ; 12:2, s. 312-319
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Forskningsöversikt (refereegranskat)abstract
- Soil is likely the most complex ecosystem on earth. Despite the global importance and extraordinary diversity of soils, they have been notoriously challenging to study. We show how pioneering microfluidic techniques provide new ways of studying soil microbial ecology by allowing simulation and manipulation of chemical conditions and physical structures at the microscale in soil model habitats.The ISME Journal advance online publication, 14 November 2017; doi:10.1038/ismej.2017.184.
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| 2. |
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| 3. |
- Ohlsson, Pelle, et al.
(författare)
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Acoustic impedance matched buffers enable separation of bacteria from blood cells at high cell concentrations
- 2018
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 8:1
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Tidskriftsartikel (refereegranskat)abstract
- Sepsis is a common and often deadly systemic response to an infection, usually caused by bacteria. The gold standard for finding the causing pathogen in a blood sample is blood culture, which may take hours to days. Shortening the time to diagnosis would significantly reduce mortality. To replace the time-consuming blood culture we are developing a method to directly separate bacteria from red and white blood cells to enable faster bacteria identification. The blood cells are moved from the sample flow into a parallel stream using acoustophoresis. Due to their smaller size, the bacteria are not affected by the acoustic field and therefore remain in the blood plasma flow and can be directed to a separate outlet. When optimizing for sample throughput, 1 ml of undiluted whole blood equivalent can be processed within 12.5 min, while maintaining the bacteria recovery at 90% and the blood cell removal above 99%. That makes this the fastest label-free microfluidic continuous flow method per channel to separate bacteria from blood with high bacteria recovery (>80%). The high throughput was achieved by matching the acoustic impedance of the parallel stream to that of the blood sample, to avoid that acoustic forces relocate the fluid streams.
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| 4. |
- Ohlsson, Pelle, et al.
(författare)
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Integrated Acoustic Separation, Enrichment, and Microchip Polymerase Chain Reaction Detection of Bacteria from Blood for Rapid Sepsis Diagnostics
- 2016
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Ingår i: Analytical Chemistry. - : American Chemical Society (ACS). - 0003-2700 .- 1520-6882. ; 88:19, s. 9403-9411
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Tidskriftsartikel (refereegranskat)abstract
- This paper describes an integrated microsystem for rapid separation, enrichment, and detection of bacteria from blood, addressing the unmet clinical need for rapid sepsis diagnostics. The blood sample is first processed in an acoustophoresis chip, where red blood cells are focused to the center of the channel by an acoustic standing wave and sequentially removed. The bacteria-containing plasma proceeds to a glass capillary with a localized acoustic standing wave field where the bacteria are trapped onto suspended polystyrene particles. The trapped bacteria are subsequently washed while held in the acoustic trap and released into a polymer microchip containing dried polymerase chain reaction (PCR) reagents, followed by thermocycling for target sequence amplification. The entire process is completed in less than 2 h. Testing with Pseudomonas putida spiked into whole blood revealed a detection limit of 1000 bacteria/mL for this first-generation analysis system. In samples from septic patients, the system was able to detect Escherichia coli in half of the cases identified by blood culture. This indicates that the current system detects bacteria in patient samples in the upper part of the of clinically relevant bacteria concentration range and that a further developed acoustic sample preparation system may open the door for a new and faster automated method to diagnose sepsis.
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| 5. |
- Petersson, Klara, et al.
(författare)
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Acoustofluidic hematocrit determination
- 2018
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Ingår i: Analytica Chimica Acta. - : Elsevier BV. - 0003-2670. ; 1000, s. 199-204
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Tidskriftsartikel (refereegranskat)abstract
- Hematocrit (HCT) measurements of blood from patients, blood donors and athletes are routinely performed on a daily basis. These measurements are often performed in centralized hospital labs by whole blood analyzers, which leads to long time-to-result. On site measurements, based on centrifugation can be done, but these assays require manual handling, are slow and can just measure HCT in contrast to the central lab whole blood analyzers. In this work, we present a microfluidic based method to measure HCT in blood samples by acoustic separation of whole blood into discrete regions of plasma and red blood cells. Comparison of the areas of the red blood cell and plasma regions gives an accurate HCT value, with a linear correlation to the centrifugation-based reference method. A readout can be performed within 2 s of acoustic actuation providing a readout accuracy of approximately 3% points (pp) HCT. Additional accuracy can be achieved by extending the acoustic actuation to 20 s, yielding an error of less than 1 pp HCT. This acoustic tool is optimal for integration into a lab-on-a-chip device with in-line measurements of different clinical parameters.
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| 6. |
- Petersson, Klara, et al.
(författare)
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Twenty second acoustofluidic whole blood hematocrit assay
- 2016
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Ingår i: 20th International Conference on Miniaturized Systems for Chemistry and Life Sciences, MicroTAS 2016. - 9780979806490 ; , s. 635-636
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Konferensbidrag (refereegranskat)abstract
- This abstract reports a novel acoustofluidic method to measure the hematocrit level of a whole blood sample within 20 seconds. The method is substantially faster than conventional centrifugation methods, has no moving parts and can be fully automated and integrated with further unit operations for analysis of blood samples at the point of care [1].
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| 7. |
- Urbansky, Anke, et al.
(författare)
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Label-free acoustophoretic enrichment of mononuclear cells from blood
- 2017
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Ingår i: MicroTAS 2017 : Savannah, Georgia, USA - Savannah, Georgia, USA. - 1556-5904. - 9780692941836 ; 2017, s. 1309-1310
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Konferensbidrag (refereegranskat)abstract
- We are reporting an efficient, label-free and continuous separation of mononuclear cells (MNC), from blood using microchip acoustophoresis. In standard PBS buffer, MNCs and red blood cells (RBC) display overlapping acoustophoretic mobilities which compromise separation of these cell types from each other. In this paper we capitalize on the fact that MNC and RBC display different acoustophysical properties. By optimizing the buffer conditions and thereby changing the acoustic contrast factor, and hence the acoustophoretic mobility of the cells, a 2800-fold enrichment of MNCs vs. RBCs with MNC recoveries up to 88% was accomplished.
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| 8. |
- Urbansky, Anke, et al.
(författare)
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Rapid and effective enrichment of mononuclear cells from blood using acoustophoresis
- 2017
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 7:1
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Tidskriftsartikel (refereegranskat)abstract
- Effective separation methods for fractionating blood components are needed for numerous diagnostic and research applications. This paper presents the use of acoustophoresis, an ultrasound based microfluidic separation technology, for label-free, gentle and continuous separation of mononuclear cells (MNCs) from diluted whole blood. Red blood cells (RBCs) and MNCs behave similar in an acoustic standing wave field, compromising acoustic separation of MNC from RBC in standard buffer systems. However, by optimizing the buffer conditions and thereby changing the acoustophoretic mobility of the cells, we were able to enrich MNCs relative to RBCs by a factor of 2,800 with MNC recoveries up to 88%. The acoustophoretic microchip can perform cell separation at a processing rate of more than 1 × 105 cells/s, corresponding to 5 μl/min undiluted whole blood equivalent. Thus, acoustophoresis can be easily integrated with further down-stream applications such as flow cytometry, making it a superior alternative to existing MNC isolation techniques.
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