A perspective on optical developments in microfluidic platforms for Caenorhabditis elegans research

Investigations were conducted to determine acute effects of Pb 2þ and Cu 2þ presented individually and collectively on zebrafish embryos. Aquatic safety testing requires a cheap, fast, and highly efficient platform for real-time evaluation of single and mixture of metal toxicity. In this study, we have developed a microfluidic system for phenotype-based evaluation of toxic effects of Pb 2þ and Cu 2þ using zebrafish (Danio rerio) embryos. The microfluidic chip is composed of a disc-shaped concentration gradient generator and 24 culture chambers, which can generate one blank solution, seven mixture concentrations, and eight single concentrations for each metal solution, thus enabling the assessment of zebrafish embryos.To test the accuracy of this new chip platform, we have examined the toxicity and teratogenicity of Pb 2þ and Cu 2þ on embryos. The individual and combined impact of Pb 2þ and Cu 2þ on zebrafish embryonic development was quantitatively assessed by recording a series of physiological indicators, such as spontaneous motion at 22 hours post fertilization (hpf), mortality at 24 hpf, heartbeat and body length at 96 hpf, etc. It was found that Pb 2þ or Cu 2þ could induce deformity and cardiovascular toxicity in zebrafish embryos and the mixture could induce more severe toxicity. This chip is a multiplexed testing apparatus that allows for the examination of toxicity and teratogenicity for substances and it also can be used as a potentially costeffective and rapid aquatic safety assessment tool. V C 2015 AIP Publishing LLC.

Section: Embryo Culturing On Chipsmentioning

confidence: 93%

Comparative toxicity of lead (Pb2+), copper (Cu2+), and mixtures of lead and copper to zebrafish embryos on a microfluidic chip

Yang

Chen

et al. 2015

“…8,9,[12][13][14][15][16][17] Moreover, microfluidic devices can be automated to handle single or a population of C. elegans in a high-throughput fashion, which enables large-scale assays such as drug and genetic screens. [15][16][17][18][19][20][21][22] In previous work from our group, we designed a simple microfluidic device to examine the swimming behaviors of C. elegans under electric fields, termed electrotaxis, and demonstrated that changes in movement are reliable indicators of neurodegeneration and harmful effects of toxic chemicals on C. elegans health. [23][24][25] However, the inherent manual operation of the devices makes the screening process labor intensive and time consuming, which limits largely the practical application of the method.…”

Section: Introductionmentioning

confidence: 99%

An automated microfluidic system for screening Caenorhabditis elegans behaviors using electrotaxis

Gupta

Selvaganapathy

2016

Caenorhabditis elegans (C. elegans) is a widely used animal model to study mechanisms of biological processes and human diseases. To facilitate manipulations of C. elegans in the laboratory, researchers have developed various tools that permit careful monitoring of behavior and changes in cellular processes. Earlier, we had reported a novel microfluidic assay device to study the neuronal basis of movement and to investigate the effects of cellular and environmental factors that can induce degeneration in certain neurons leading to movement disorder. The system involved the use of an electric field to perform electrotaxis assays, which allows detailed examination of movement responses of animals. One of the potential uses of this system is to perform genetic and chemical screenings for neuroprotective factors; however, it could not be done due to manual operations and low throughput. In this paper, we present an integrated microfluidic system that automates screening of C. elegans behavioral response using electrotaxis. The core component of system is a multilayer poly dimethyl siloxane (PDMS) device, which enables C. elegans loading, capture, flush, release, electrotaxis, and clean sequentially with the help of other components. The system is capable of screening C. elegans, at a throughput of more than 20 worms per hour, automatically and continually without human intervention. To demonstrate the effectiveness of the system, C. elegans neuronal mutants were screened, and the phenotype data were extracted and analyzed. We envision that the automatic screening potential of the system will accelerate the study of neuroscience, drug discovery, and genetic screens in C. elegans. V C 2016 AIP Publishing LLC. [http://dx

“…Recent advances in microfluidics and microsystems [6][7][8][9][10][11][12][13][14] have further facilitated investigation into C. elegans' behavior patterns in response to controlled external stimuli. Enabled by state-of-the-art technologies, a variety of external stimuli has been independently studied as a variable in the worm's environment, including temperature, [15][16][17] chemicals, [18][19][20][21] food-related signals, 22 gas concentration, 23 electric field, 24,25 and physical obstacles.…”

Section: Introductionmentioning

confidence: 99%

An integrated platform enabling optogenetic illumination of Caenorhabditis elegans neurons and muscular force measurement in microstructured environments

Qiu

Huang

et al. 2015

Optogenetics has been recently applied to manipulate the neural circuits of Caenorhabditis elegans (C. elegans) to investigate its mechanosensation and locomotive behavior, which is a fundamental topic in model biology. In most neuron-related research, free C. elegans moves on an open area such as agar surface. However, this simple environment is different from the soil, in which C. elegans naturally dwells. To bridge up the gap, this paper presents integration of optogenetic illumination of C. elegans neural circuits and muscular force measurement in a structured microfluidic chip mimicking the C. elegans soil habitat. The microfluidic chip is essentially a ∼1 × 1 cm2 elastomeric polydimethylsiloxane micro-pillar array, configured in either form of lattice (LC) or honeycomb (HC) to mimic the environment in which the worm dwells. The integrated system has four key modules for illumination pattern generation, pattern projection, automatic tracking of the worm, and force measurement. Specifically, two optical pathways co-exist in an inverted microscope, including built-in bright-field illumination for worm tracking and pattern generation, and added-in optogenetic illumination for pattern projection onto the worm body segment. The behavior of a freely moving worm in the chip under optogenetic manipulation can be recorded for off-line force measurements. Using wild-type N2 C. elegans, we demonstrated optical illumination of C. elegans neurons by projecting light onto its head/tail segment at 14 Hz refresh frequency. We also measured the force and observed three representative locomotion patterns of forward movement, reversal, and omega turn for LC and HC configurations. Being capable of stimulating or inhibiting worm neurons and simultaneously measuring the thrust force, this enabling platform would offer new insights into the correlation between neurons and locomotive behaviors of the nematode under a complex environment.