Limits...
Two-Dimensional Algal Collection and Assembly by Combining AC-Dielectrophoresis with Fluorescence Detection for Contaminant-Induced Oxidative Stress Sensing.

Siebman C, Velev OD, Slaveykova VI - Biosensors (Basel) (2015)

Bottom Line: An alternative current (AC) dielectrophoretic lab-on-chip setup was evaluated as a rapid tool of capture and assembly of microalga Chlamydomonas reinhardtii in two-dimensional (2D) close-packed arrays.The results showed significant increase of the cellular ROS when C. reinhardtii was exposed to high concentrations of methylmercury, CuO-NPs, and 10⁻⁵ M Cu.Overall, this study demonstrates the potential of combining AC-dielectrophoretically assembled two-dimensional algal structures with cell metabolic analysis using fluorescence staining, as a rapid analytical tool for probing the effect of contaminants in highly impacted environment.

View Article: PubMed Central - PubMed

Affiliation: Environmental Biogeochemistry and Ecotoxicology, Institute F.-A. Forel, Earth and Environmental Science, Faculty of Sciences, University of Geneva, 10 route de Suisse, Versoix CH-1290, Switzerland. coralie.suscillon@unige.ch.

ABSTRACT
An alternative current (AC) dielectrophoretic lab-on-chip setup was evaluated as a rapid tool of capture and assembly of microalga Chlamydomonas reinhardtii in two-dimensional (2D) close-packed arrays. An electric field of 100 V·cm⁻¹, 100 Hz applied for 30 min was found optimal to collect and assemble the algae into single-layer structures of closely packed cells without inducing cellular oxidative stress. Combined with oxidative stress specific staining and fluorescence microscopy detection, the capability of using the 2D whole-cell assembly on-chip to follow the reactive oxygen species (ROS) production and oxidative stress during short-term exposure to several environmental contaminants, including mercury, methylmercury, copper, copper oxide nanoparticles (CuO-NPs), and diuron was explored. The results showed significant increase of the cellular ROS when C. reinhardtii was exposed to high concentrations of methylmercury, CuO-NPs, and 10⁻⁵ M Cu. Overall, this study demonstrates the potential of combining AC-dielectrophoretically assembled two-dimensional algal structures with cell metabolic analysis using fluorescence staining, as a rapid analytical tool for probing the effect of contaminants in highly impacted environment.

Show MeSH

Related in: MedlinePlus

(a) Schematics of the experimental set-up. The four orthogonally stainless steel needle electrodes were connected in pairs to the generator and amplifier. The electric field was applied to one pair of electrodes and was switched to the other pair every 2 min allowing the formation of 2D-cell assembly. The cells and media are confined in a microfluidic chamber of silicone rubber (red) with optically transparent top; (b) Transverse section of the microfluidic chamber. The 2D-assembly of cells formed in the 5 mm-gap of the four point needle electrodes is observed by microscope using bright field and fluorescence channel FITC. The chamber and the cell sizes are not to scale; (c) Experimental plan used to test the effect of the collection time on the cell’s oxidative status.
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4493552&req=5

biosensors-05-00319-f001: (a) Schematics of the experimental set-up. The four orthogonally stainless steel needle electrodes were connected in pairs to the generator and amplifier. The electric field was applied to one pair of electrodes and was switched to the other pair every 2 min allowing the formation of 2D-cell assembly. The cells and media are confined in a microfluidic chamber of silicone rubber (red) with optically transparent top; (b) Transverse section of the microfluidic chamber. The 2D-assembly of cells formed in the 5 mm-gap of the four point needle electrodes is observed by microscope using bright field and fluorescence channel FITC. The chamber and the cell sizes are not to scale; (c) Experimental plan used to test the effect of the collection time on the cell’s oxidative status.

Mentions: DEP assembly experiments were performed with four-point needle electrodes separated by a 5 mm-gap and orthogonally arranged around a transparent top microfluidic chamber of 2 mm-height (HybriWell Incubation Chamber, BioCat GmbH, Heidelberg, Germany) (Figure 1a).


Two-Dimensional Algal Collection and Assembly by Combining AC-Dielectrophoresis with Fluorescence Detection for Contaminant-Induced Oxidative Stress Sensing.

Siebman C, Velev OD, Slaveykova VI - Biosensors (Basel) (2015)

(a) Schematics of the experimental set-up. The four orthogonally stainless steel needle electrodes were connected in pairs to the generator and amplifier. The electric field was applied to one pair of electrodes and was switched to the other pair every 2 min allowing the formation of 2D-cell assembly. The cells and media are confined in a microfluidic chamber of silicone rubber (red) with optically transparent top; (b) Transverse section of the microfluidic chamber. The 2D-assembly of cells formed in the 5 mm-gap of the four point needle electrodes is observed by microscope using bright field and fluorescence channel FITC. The chamber and the cell sizes are not to scale; (c) Experimental plan used to test the effect of the collection time on the cell’s oxidative status.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4493552&req=5

biosensors-05-00319-f001: (a) Schematics of the experimental set-up. The four orthogonally stainless steel needle electrodes were connected in pairs to the generator and amplifier. The electric field was applied to one pair of electrodes and was switched to the other pair every 2 min allowing the formation of 2D-cell assembly. The cells and media are confined in a microfluidic chamber of silicone rubber (red) with optically transparent top; (b) Transverse section of the microfluidic chamber. The 2D-assembly of cells formed in the 5 mm-gap of the four point needle electrodes is observed by microscope using bright field and fluorescence channel FITC. The chamber and the cell sizes are not to scale; (c) Experimental plan used to test the effect of the collection time on the cell’s oxidative status.
Mentions: DEP assembly experiments were performed with four-point needle electrodes separated by a 5 mm-gap and orthogonally arranged around a transparent top microfluidic chamber of 2 mm-height (HybriWell Incubation Chamber, BioCat GmbH, Heidelberg, Germany) (Figure 1a).

Bottom Line: An alternative current (AC) dielectrophoretic lab-on-chip setup was evaluated as a rapid tool of capture and assembly of microalga Chlamydomonas reinhardtii in two-dimensional (2D) close-packed arrays.The results showed significant increase of the cellular ROS when C. reinhardtii was exposed to high concentrations of methylmercury, CuO-NPs, and 10⁻⁵ M Cu.Overall, this study demonstrates the potential of combining AC-dielectrophoretically assembled two-dimensional algal structures with cell metabolic analysis using fluorescence staining, as a rapid analytical tool for probing the effect of contaminants in highly impacted environment.

View Article: PubMed Central - PubMed

Affiliation: Environmental Biogeochemistry and Ecotoxicology, Institute F.-A. Forel, Earth and Environmental Science, Faculty of Sciences, University of Geneva, 10 route de Suisse, Versoix CH-1290, Switzerland. coralie.suscillon@unige.ch.

ABSTRACT
An alternative current (AC) dielectrophoretic lab-on-chip setup was evaluated as a rapid tool of capture and assembly of microalga Chlamydomonas reinhardtii in two-dimensional (2D) close-packed arrays. An electric field of 100 V·cm⁻¹, 100 Hz applied for 30 min was found optimal to collect and assemble the algae into single-layer structures of closely packed cells without inducing cellular oxidative stress. Combined with oxidative stress specific staining and fluorescence microscopy detection, the capability of using the 2D whole-cell assembly on-chip to follow the reactive oxygen species (ROS) production and oxidative stress during short-term exposure to several environmental contaminants, including mercury, methylmercury, copper, copper oxide nanoparticles (CuO-NPs), and diuron was explored. The results showed significant increase of the cellular ROS when C. reinhardtii was exposed to high concentrations of methylmercury, CuO-NPs, and 10⁻⁵ M Cu. Overall, this study demonstrates the potential of combining AC-dielectrophoretically assembled two-dimensional algal structures with cell metabolic analysis using fluorescence staining, as a rapid analytical tool for probing the effect of contaminants in highly impacted environment.

Show MeSH
Related in: MedlinePlus