New Methods of Removing Debris and High Throughput Counting of Cyst Nematode Eggs Extracted from Field Soil
The soybean cyst nematode (SCN), Heterodera glycines, is the most damaging pathogen of soybeans in the United States. To assess the severity of nematode infestations in the field, SCN egg population densities are determined. Cysts (dead females) of the nematode must be extracted from soil samples and then ground to extract the eggs within. Sucrose centrifugation commonly is used to separate debris from suspensions of extracted nematode eggs. We present a method using OptiPrep as a density gra...
Root Chip for Growth and Imaging of Arabidopsis Plants
We describe a microfluidic platform that can be used to study the hydroponic growth of Arabidopsis plants with high-resolution visualization of root development and root-pathogen interactions. The platform comprises a set of parallel microchannels with individual input/output ports, where 1-day old germinated seedlings are initially placed. Under optimal conditions, a root system grows in each microchannel and its images are recorded over a 198-h period. Different concentrations of plant g...
Plant Chip for Simultaneous Root growth and Root Imaging
We describe a microfluidic platform that can be used to study the hydroponic growth of Arabidopsis plants with high-resolution visualization of root development and root-pathogen interactions. The platform comprises a set of parallel microchannels with individual input/output ports, where 1-day old germinated seedlings are initially placed. Under optimal conditions, a root system grows in each microchannel and its images are recorded over a 198-h period. Different concentrations of plant g...
Reconfigurable Switch or Valve for Microfluidics
A method to create smart and flexible switches for the regulation of liquid flow across multiple channels is essential in paper microfluidics. Prior approaches are hampered by long response times, high actuation fluid volumes, and external control circuitry. To diminish these problems, we designed a distinctive actuator device fashioned entirely from chromatography paper and featuring folds. The fold can be selectively wetted by an actuation fluid at either the crest or trough, resulting in t...
Fast, reconfigurable switch for paper microfluidics
A method to create smart and flexible switches for the regulation of liquid flow across multiple channels is essential in paper microfluidics. Prior approaches are hampered by long response times, high actuation fluid volumes, and external control circuitry. To diminish these problems, we designed a distinctive actuator device fashioned entirely from chromatography paper and featuring folds. The fold can be selectively wetted by an actuation fluid at either the crest or trough, resulting in t...
NanoCharge DNA Sensor - Folded Floating Gate CMOS Biosensor
A CMOS biosensor with a folded floating-gate is created to detect charged biochemical molecules. It contains a FET, a control-gate and a sensing area. The floating-gate spans the whole device, allowing the sensing area to be placed on top of the FET, resulting in a decrease of the device's total area. The device is sensitive to the polarity and quantity of charged poly amino acids and could be used for electronic recognition of temporal and spatial migration of charges, such as in biological ...
Extended Floating Gate CMOS BioFET transistor as a nano charge sensor
A CMOS biosensor with a folded floating-gate is created to detect charged biochemical molecules. It contains a FET, a control-gate and a sensing area. The floating-gate spans the whole device, allowing the sensing area to be placed on top of the FET, resulting in a decrease of the device's total area. The device is sensitive to the polarity and quantity of charged poly amino acids and could be used for electronic recognition of temporal and spatial migration of charges, such as in biological ...
Microfluidics for Drug Screening and Paralysis of Parasites
The emergence of new drugs is often driven by the escalating resistance of parasites to existing drugs and the accessibility of more advanced technology platforms. Microfluidic devices have allowed for quicker testing of compounds, regulated sampling/sorting of entire animals, and automated behavioral pattern detection. In the majority of microfluidic devices, the effects of drugs on small animals (e.g. Caenorhabditis elegans)elegant are quantified by an endpoint, dose response curve that sho...
Microfluidics to identify drug dose response and LD50 of parasites
The emergence of new drugs is often driven by the escalating resistance of parasites to existing drugs and the accessibility of more advanced technology platforms. Microfluidic devices have allowed for quicker testing of compounds, regulated sampling/sorting of entire animals, and automated behavioral pattern detection. In the majority of microfluidic devices, the effects of drugs on small animals (e.g. Caenorhabditis elegans)elegant are quantified by an endpoint, dose response curve that sho...
Effect of Static Magnetic Field on Parasites
This study uses the model organism, C. elegans, to investigate its sensitivity and response to static magnetic fields. Wild-type C. elegans are put into microfluidic channels and exposed to permanent magnets for five cycles of thirty-second time intervals at field strengths ranging from 5 milli Tesla to 120 milli Tesla. Recorded and analyzed with custom software, the results of the worm's movement - the average velocity, turning and curling percentage - were compared to control experiments. S...
Characterizing the Effect of Static Magnetic Fields on Parasites
This study uses the model organism, C. elegans, to investigate its sensitivity and response to static magnetic fields. Wild-type C. elegans are put into microfluidic channels and exposed to permanent magnets for five cycles of thirty-second time intervals at field strengths ranging from 5 milli Tesla to 120 milli Tesla. Recorded and analyzed with custom software, the results of the worm's movement - the average velocity, turning and curling percentage - were compared to control experiments...
Electrotaxis to realize a switchable valve for parasitic worms
We present the NERV, a nonmechanical, unidirectional valve, to control the locomotion of Caenorhabditis elegant (C. elegans) in microfluidic devices. This valve is created by establishing a region of lateral electric field which can be toggled between on and off states. We observed that C. elegans do not prefer to advance into this region when the field lines are facing their movement, so when they reach the boundary of the NERV, they partway enter the field, retreat, and switch direction. We...
Nematode Electrotactic Response Valve (NERV) for Parasitic Worms
A nonmechanical, unidirectional valve, the Nematode Electrotactic-Response Valve (NERV), has been developed to control the motion of Caenorhabditis elegant (C. elegans) in microfluidic devices. By forming a region of lateral electric field, which can be switched or reversed, the NERV prevents worms from advancing through it if the field lines are angled against the movement of the worms. Upon arriving at the boundary of the NERV, the worms penetrate the field area briefly and then retreat and...
Microfluidic chip for analyzing the effects of drugs and their dosage on the locomotion behavior of parasitic worms
This new microfluidic platform offers a more sensitive method for screening drugs and their effects on the locomotion of free living and parasitic nematodes. The chip is capable of monitoring four nematode parameters (number of worms responsive, number of worms leaving the drug well, average worm velocity and time until unresponsiveness) to provide a more detailed analysis and resolution of drug resistance. The drug screening experiment is divided into three parts: pre-exposure study, dose ex...
Microfluidic platform to analyze the effects of drugs on the locomotion behavior of parasites
This research paper presents a microfluidic platform for analyzing the effects of drugs and their dosage on the locomotion behavior of both free-living and parasitic nematodes. The chip provides a higher level of sensitivity for drug screening and can monitor four different nematode parameters in real time. It is a cross-species and cross-drug platform that is far more sophisticated than existing nematode motility and migration assays. The device consists of two parts: behavioral microchannel...
