| 1. |
- Emmelkamp, J., et al.
(författare)
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The potential of autofluorescence for the detection of single living cells for label-free cell sorting in microfluidic systems
- 2004
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Ingår i: Electrophoresis. - : Wiley. - 0173-0835 .- 1522-2683. ; 25:21-22, s. 3740-3745
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Tidskriftsartikel (refereegranskat)abstract
- A novel method for studying unlabeled living mammalian cells based on their autofluorescence (AF) signal in a prototype microfluidic device is presented. When combined, cellular AF detection and microfluidic devices have the potential to facilitate high-throughput analysis of different cell populations. To demonstrate this, unlabeled cultured cells in microfluidic devices were excited with a 488 nm excitation light and the AF emission (> 505 nm) was detected using a confocal fluorescence microscope (CFM). For example, a simple microfluidic three-port glass microstructure was used together with conventional electroosmotic flow (EOF) to switch the direction of the fluid flow. As a means to test the potential of AF-based cell sorting in this microfluidic device, granulocytes were successfully differentiated from human red blood cells (RBCs) based on differences in AF This study demonstrated the use of a simple microfabricated device to perform high-throughput live cell detection and differentiation without the need for cell-specific fluorescent labeling dyes and thereby reducing the sample preparation time. Hence, the combined use of microfluidic devices and cell AF may have many applications in single-cell analysis.
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| 2. |
- Valero, A., et al.
(författare)
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Apoptotic cell death dynamics of HL60 cells studied using a microfluidic cell trap device
- 2005
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Ingår i: Lab on a Chip. - : Royal Society of Chemistry (RSC). - 1473-0197 .- 1473-0189. ; 5:1, s. 49-55
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Tidskriftsartikel (refereegranskat)abstract
- This paper presents the design, fabrication and first results of a microfluidic cell trap device for analysis of apoptosis. The microfluidic silicon-glass chip enables the immobilization of cells and real-time monitoring of the apoptotic process. Induction of apoptosis, either electric field mediated or chemically induced with tumour necrosis factor (TNF-alpha), in combination with cycloheximide (CHX), was addressed. Exposure of cells to the appropriate fluorescent dyes, FLICA and PI, allows one to discriminate between viable, apoptotic and necrotic cells. The results showed that the onset of apoptosis and the transitions during the course of the cell death cascade were followed in chemically induced apoptotic HL60 cells. For the case of electric field mediated cell death, the distinction between apoptotic and necrotic stage was not clear. This paper presents the first results to analyse programmed cell death dynamics using this apoptosis chip and a first step towards an integrated apoptosis chip for high-throughput drug screening on a single cellular level.
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| 3. |
- Wolbers, F., et al.
(författare)
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Apoptosis induced kinetic changes in autofluorescence of cultured HL60 cells-possible application for single cell analysis on chip
- 2004
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Ingår i: Apoptosis (London). - 1360-8185 .- 1573-675X. ; 9:6, s. 749-755
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: This paper presents a new method using natural cellular fluorescence (autofluorescence, AF) to study apoptosis. Measurement of AF reduces sample preparation time and avoids cellular toxicity due to the fact that no labelling is required. Methods: Human promyelocytic leukemic HL60 cells were incubated with camptothecin (CPT), tumour necrosis factor (TNF)-alpha in combination with cycloheximide (CHX), or irradiated with 6 or 10 Gray, during varying time periods, to initiate apoptosis. AF was measured at the flow cytometer. Results: Induction of apoptosis results in the shrinkage of the cell and the fragmentation into apoptotic bodies. With flow cytometry, 4 subpopulations, viable, early apoptotic, late apoptotic and the necrotic cells, can be distinguished. Induction of apoptosis results in a decrease in AF intensity compared to untreated HL60 cells, especially seen in the late apoptotic subpopulation. The AF intensity is found to decrease significantly in time (between 2 h and 24 h) for all the four apoptotic inducers used. Conclusions: Our results show that it is possible to specifically measure the apoptotic-induced kinetic changes in AF in HL60 cells. A decrease in AF intensity is seen from 2 h till 24 h. These results open a door for future developments in single-cell analysis.
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| 4. |
- Wolbers, F., et al.
(författare)
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Microfluidic apoptosis chip for drug screening to improve and personalize cancer therapy
- 2008
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Ingår i: 12th International Conference on Miniaturized Systems for Chemistry and Life Sciences - The Proceedings of MicroTAS 2008 Conference. - : Chemical and Biological Microsystems Society. ; , s. 549-551
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Konferensbidrag (refereegranskat)abstract
- Currently, the knowledge on breast cancer treatment is increasing, however, there are still hardly any assays present to match patients to the right form of therapy to enhance the therapeutic effectiveness. Therefore a microfluidic device is developed to analyze the hormonal and chemosensitivity of first breast cancer cell lines (MCF-7) and in a later stage a patients' own tumor cells. The apoptotic inducers tumor necrosis factor-α, in combination with cycloheximide, and staurosporine stained MCF-7 cells positive for Annexin V and PI, and showed a decrease in area coverage as compared to untreated cells.
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