| 1. |
- Bertilson, Michael, et al.
(författare)
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Laboratory soft-x-ray microscope for cryotomography of biological specimens
- 2011
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Ingår i: Optics Letters. - 0146-9592 .- 1539-4794. ; 36:14, s. 2728-2730
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Tidskriftsartikel (refereegranskat)abstract
- Soft-x-ray cryotomography allows quantitative and high-resolution three-dimensional imaging of intact unstained cells. To date, the method relies on synchrotron-radiation sources, which limits accessibility for researchers. Here we present a laboratory water-window microscope for cryotomography. It is based on a lambda = 2.48nm liquid-jet laser-plasma source, a normal-incidence multilayer condenser, a 30nm zone-plate objective, and a cryotilt sample holder. We demonstrate high-resolution imaging, as well as quantitative tomographic imaging, of frozen intact cells. The reconstructed tomogram of the intracellular local absorption coefficient shows details down to similar to 100nm.
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| 2. |
- Christakou, Athanasia. E., et al.
(författare)
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Aggregation and long-term positioning of cells by ultrasound in a multi-well microchip for high-resolution imaging of the natural killer cell immune synapse
- 2011
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Ingår i: 15th International Conference on Miniaturized Systems for Chemistry and Life Sciences 2011, MicroTAS 2011. - 9781618395955 ; , s. 329-331
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Konferensbidrag (refereegranskat)abstract
- In this study we investigate the ability of Natural Killer (NK) cells to form ultrasound-mediated intercellular contacts with target cells in a multi-well microdevice by high-resolution confocal-microscopy imaging of inhibitory immune synapses. Furthermore, we compare the NK-Target cell cluster migration with and without ultrasound actuation. Experiments indicate that clusters of cells are positioned and maintained centered in the wells for 17 hours when they are exposed continuously to ultrasound. Our system can be used for both screening high numbers of events in low resolution and also for high resolution imaging of long term cell-cell interactions.
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| 3. |
- Ohlin, Mathias, et al.
(författare)
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Controlling acoustic streaming in a multi-well microplate for improving live cell assays
- 2011
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Ingår i: 15th International Conference on Miniaturized Systems for Chemistry and Life Sciences 2011, MicroTAS 2011. - 9781618395955 ; , s. 1612-1614
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Konferensbidrag (refereegranskat)abstract
- Acoustic streaming in a multi-well microplate is investigated using two different ultrasonic actuation frequency-schemes: Single-frequency and frequency-modulation. The streaming is tracked by the use of 1 μm fluorescent polymer beads and micro-particle image velocimetry. The suspension also contained human B cells for studying the acoustic trapping and aggregation performance simultaneously with the acoustic streaming. Our results show a significant difference in the acoustic streaming between the two ultrasonic actuation schemes. A rotational fluid flow speed decreased a factor of 30 when frequency-modulation was applied compared to single-frequency actuation without apparently interfering with the acoustic cell trapping function.
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