High-throughput sorting of eggs for synchronization of C. elegans in a microfluidic spiral chip (original) (raw)

Microfluidic laboratories for C. elegans enhance fundamental studies in biology

Rsc Advances, 2014

The in vivo analysis of a small multicellular organism such as the nematode Caenorhabditis elegans, enables fundamental biomedical and environmental studies of a complete organism under normal physiological conditions. Continuous advancements in photonics, electronics, as well as the material sciences, are paving the way towards miniaturized bioanalytical systems, known as labs-on-a-chip (LOC). These microfluidic technologies facilitate the manipulation and study of nematodes in a precise, real-time, portable, and cost-effective manner, potentially for high throughput operation. In this paper we review all currently available "worm-on-a-chip" miniaturized systems that address the manipulation, detection, and study of the sensory response of C. elegans, and take a close look at their advantages, application challenges, and scientific potential. The paper aims to consolidate recent results of dedicated worm microsystems that target a better understanding of C. elegans.

Microfluidic Devices in Advanced Caenorhabditis elegans Research

Molecules, 2016

The study of model organisms is very important in view of their potential for application to human therapeutic uses. One such model organism is the nematode worm, Caenorhabditis elegans. As a nematode, C. elegans have~65% similarity with human disease genes and, therefore, studies on C. elegans can be translated to human, as well as, C. elegans can be used in the study of different types of parasitic worms that infect other living organisms. In the past decade, many efforts have been undertaken to establish interdisciplinary research collaborations between biologists, physicists and engineers in order to develop microfluidic devices to study the biology of C. elegans. Microfluidic devices with the power to manipulate and detect bio-samples, regents or biomolecules in micro-scale environments can well fulfill the requirement to handle worms under proper laboratory conditions, thereby significantly increasing research productivity and knowledge. The recent development of different kinds of microfluidic devices with ultra-high throughput platforms has enabled researchers to carry out worm population studies. Microfluidic devices primarily comprises of chambers, channels and valves, wherein worms can be cultured, immobilized, imaged, etc. Microfluidic devices have been adapted to study various worm behaviors, including that deepen our understanding of neuromuscular connectivity and functions. This review will provide a clear account of the vital involvement of microfluidic devices in worm biology.

Microfluidic Chip for High Efficiency Microinjection of Caenorhabditis elegans

2019

The terrestrial nematode, Caenorhabditis elegans, is an invaluable model organism for the study of molecular and cellular processes due to their small size, rapid generation time, easy cultivation, and invariant cell number. Additionally, 40% of genes known to be associated with human disease have clear orthologs in the C. elegans genome. In C. elegans genetics research, microinjection of genetic material into the worms is critical. Although an established technique, manual microinjection is tedious, low-throughput, and requires an expert researcher. This thesis details a novel microfluidic device designed to perform high-throughput microinjection. This two-layer, PDMS-based chip integrates microfluidic elements to control worm sorting, reduction of immobilization time and stress, and novel on-chip microinjection using only a positive pressure source. Our project aim is to increase microinjection efficiency, consistency, and accessibility to researchers of all experience levels in order to advance genetics research and genetic engineering technology in C. elegans. Preliminary results are promising, as our on-chip microinjection device has been able to successfully inject dye into C. elegans animals.

An Automated Microfluidic Multiplexer for Fast Delivery of C. elegans Populations from Multiwells

PLoS ONE, 2013

Automated biosorter platforms, including recently developed microfluidic devices, enable and accelerate highthroughput and/or high-resolution bioassays on small animal models. However, time-consuming delivery of different organism populations to these systems introduces a major bottleneck to executing large-scale screens. Current population delivery strategies rely on suction from conventional well plates through tubing periodically exposed to air, leading to certain disadvantages: 1) bubble introduction to the sample, interfering with analysis in the downstream system, 2) substantial time drain from added bubble-cleaning steps, and 3) the need for complex mechanical systems to manipulate well plate position. To address these concerns, we developed a multiwell-format microfluidic platform that can deliver multiple distinct animal populations from on-chip wells using multiplexed valve control. This Population Delivery Chip could operate autonomously as part of a relatively simple setup that did not require any of the major mechanical moving parts typical of plate-handling systems to address a given well. We demonstrated automatic serial delivery of 16 distinct C. elegans worm populations to a single outlet without introducing any bubbles to the samples, causing cross-contamination, or damaging the animals. The device achieved delivery of more than 90% of the population preloaded into a given well in 4.7 seconds; an order of magnitude faster than delivery modalities in current use. This platform could potentially handle other similarly sized model organisms, such as zebrafish and drosophila larvae or cellular micro-colonies. The device's architecture and microchannel dimensions allow simple expansion for processing larger numbers of populations. Citation: Ghorashian N, Gökçe SK, Guo SX, Everett WN, Ben-Yakar A (2013) An Automated Microfluidic Multiplexer for Fast Delivery of C. elegans Populations from Multiwells. PLoS ONE 8(9): e74480.

Lifespan-on-a-chip: microfluidic chambers for performing lifelong observation of C. elegans

Lab on A Chip, 2010

This article describes the fabrication of a microfluidic device for the liquid culture of many individual nematode worms (Caenorhabditis elegans) in separate chambers. Each chamber houses a single worm from the fourth larval stage until death, and enables examination of a population of individual worms for their entire adult lifespans. Adjacent to the chambers, the device includes microfluidic worm clamps, which enable periodic, temporary immobilization of each worm. The device made it possible to track changes in body size and locomotion in individual worms throughout their lifespans. This ability to perform longitudinal measurements within the device enabled the identification of age-related phenotypic changes that correlate with lifespan in C. elegans.

A microfluidic device and automatic counting system for the study of C. elegans reproductive aging

The nematode Caenorhabditis elegans (C. elegans) is an excellent model to study reproductive aging because of its short life span, its cessation of reproduction in mid-adulthood, and the strong conservation of pathways that regulate longevity. During its lifetime, a wild-type C. elegans hermaphrodite usually lays about 200-300 self-fertilized hatchable eggs, which mainly occurs in the first three to five days of adulthood. Here, we report the development of a microfluidic assay and a real-time, automatic progeny counting system that records progeny counting information from many individual C. elegans hermaphrodites. This system offers many advantages compared to conventional plate assays. The flow of nonproliferating bacteria not only feeds the worms but also flushes the just-hatched young progeny through a filter that separates mothers from their offspring. The progeny that are flushed out of the chamber are detected and recorded using a novel algorithm. In our current design, one device contains as many as 16 individual chambers. Here we show examples of real-time progeny production information from wild-type (N2) and daf-2 (insulin receptor) mutants. We believe that this system has the potential to become a powerful, high time-resolution tool to study the detailed reproduction of C. elegans.

High-throughput, motility-based sorter for microswimmers such as C. elegans

Lab on a chip, 2015

Animal motility varies with genotype, disease, aging, and environmental conditions. In many studies, it is desirable to carry out high throughput motility-based sorting to isolate rare animals for, among other things, forward genetic screens to identify genetic pathways that regulate phenotypes of interest. Many commonly used screening processes are labor-intensive, lack sensitivity, and require extensive investigator training. Here, we describe a sensitive, high throughput, automated, motility-based method for sorting nematodes. Our method is implemented in a simple microfluidic device capable of sorting thousands of animals per hour per module, and is amenable to parallelism. The device successfully enriches for known C. elegans motility mutants. Furthermore, using this device, we isolate low-abundance mutants capable of suppressing the somnogenic effects of the flp-13 gene, which regulates C. elegans sleep. By performing genetic complementation tests, we demonstrate that our moti...

Microfluidics for the analysis of behavior, nerve regeneration, and neural cell biology in C. elegans

Current Opinion in Neurobiology, 2009

The nematode Caenorhabditis elegans is a widely adopted model organism for studying various neurobiological processes at the molecular and cellular level in vivo. With a small, flexible, and continuously moving body, the manipulation of C. elegans becomes a challenging task. In this review, we highlight recent advances in microfluidic technologies for the manipulation of C. elegans. These new family of microfluidic chips are capable of handling single or populations of worms in a high-throughput fashion and accurately controlling their microenvironment. So far, they have been successfully used to study neural circuits and behavior, to perform large-scale phetotyping and morphology-based screens as well as to understand axon regeneration after injury. We envision that microfluidic chips can further be used to study different aspects of the C. elegans nervous system, extending from fundamental understanding of behavioral dynamics to more complicated biological processes such as neural aging and learning and memory.

Detecting and Trapping of a Single C. elegans Worm in a Microfluidic Chip for Automated Microplate Dispensing

Journal of Laboratory Automation, 2016

Microfluidic devices offer new technical possibilities for a precise manipulation of Caenorhabditis elegans due to the comparable length scale. C. elegans is a small, free-living nematode worm that is a popular model system for genetic, genomic, and high-throughput experimental studies of animal development and neurobiology. In this paper, we demonstrate a microfluidic system in polydimethylsiloxane (PDMS) for dispensing of a single C. elegans worm into a 96-well plate. It consists of two PDMS layers, a flow and a control layer. Using five microfluidic pneumatic valves in the control layer, a single worm is trapped upon optical detection with a pair of optical fibers integrated perpendicular to the constriction channel and then dispensed into a microplate well with a dispensing tip attached to a robotic handling system. Due to its simple design and facile fabrication, we expect that our microfluidic chip can be expanded to a multiplexed dispensation system of C. elegans worms for hi...

A continuous-flow C. elegans sorting system with integrated optical fiber detection and laminar flow switching

2014

We present a high-throughput continuous-flow C. elegans sorting device that works based on integrated optical fiber detection and laminar flow switching. Two types of genetically engineered nematodes are allowed to flow into the device and their genotypes are detected based on their fluorescence, without the need for immobilization, by integrated optical fibers. A novel dynamic fluidic switch sorts the nematodes to desired outlets. By changing input pressures of the control inlets, the laminar flow path is altered to steer the nematodes to appropriate outlets. Compared to previously reported microfluidic C. elegans sorting devices, sorting in this system is conducted in a continuous flow environment without any immobilization technique or need for multilayer mechanical valves to open and close the outlets. The continuous flow sorter not only increases the throughput but also avoids any kind of invasive or possibly damaging mechanical or chemical stimulus. We have characterized both the detection and the switching accuracy of the sorting device at different flow rates, and efficiencies approaching 100% can be achieved with a high throughput of about one nematode per second. To confirm that there was no significant damage to C. elegans following sorting, we recovered the sorted worms, finding no deaths and no differences in behavior and propagation compared to control.