Presentation Title

Monitoring the Growth and Health of Single Daphnia Using Vibrating Tube Sensors

Presenter Information

Christopher RicoFollow

Faculty Mentor

William Grover

Start Date

23-11-2019 10:15 AM

End Date

23-11-2019 10:30 AM

Location

Markstein 105

Session

oral 2

Type of Presentation

Oral Talk

Subject Area

engineering_computer_science

Abstract

Daphnia magna are a model organism used for a variety of applications. These freshwater crustaceans are prime candidates for toxicity monitoring and have recently gained momentum as model organisms for understanding biological pathways while introduced to various pharmaceuticals. Daphnia have been used for these studies because of their ease of use, small nature, short lifespan, ability to asexually reproduce, and their transparency, which allows for relatively easy analysis using microscopy. While microscopy is a useful tool to examine a qualitative difference in the organism, researchers are limited when trying to quantitatively understand the differences between the samples. We show that a vibrating tube sensor can offer developmental insights of a model organism by monitoring its physical properties like mass, volume, and density. For these types of measurements, a glass tube vibrates at its natural resonance frequency, which is a function of the glass tube. When a sample is introduced into the vibrating tube, the additional mass will inversely change the resonance frequency of the sensor, which can be calibrated to a buoyant mass. We can trap that object by pumping the object forwards and backwards, producing several buoyant mass measurements and a buoyant mass profile over time. Preliminary results show that the buoyant mass of Daphnia magna in water can range from 12 to 22 micrograms. While mass monitoring can be an indicator of development, the buoyant mass can change depending on many phycological changes. We hypothesize that measuring the density and volume of a model organism continuously can provide meaningful insights about the development of model organisms. In this work, we build a system capable of measuring the density of the object in real-time by measuring the object of interest in two fluids of different but known densities. From two buoyant mass measurements, the true mass (in vacuo), density, and volume of the Daphnia can be calculated using Archimedes principle. We accomplish this by building a vacuum driven fluidic circuit that can delivery two different fluids on demand. An initial fluid, typically water (density of 1.00 g/mL), is loaded into our sensor, the daphnia or any object will pass through the sensor, and a frequency change will be recorded. Once a frequency change is measured, the system will pump in a second fluid like heavy water (density of 1.10 g/mL), and a subsequent buoyant mass is measured. This data is postprocessed using a custom Python script that detects all the frequency changes and calculates the mass, volume, and density of the Daphnia over time. With this setup, we can introduce toxicants in solution and monitor the changes of the physical properties. We believe that this measurement technique can provide quantitative methods that microscopy cannot provide and that this system will allow us to gain insights into the growth and health of single model organisms which will open up interesting avenues of research that were not possible previously.

This document is currently not available here.

Share

COinS
 
Nov 23rd, 10:15 AM Nov 23rd, 10:30 AM

Monitoring the Growth and Health of Single Daphnia Using Vibrating Tube Sensors

Markstein 105

Daphnia magna are a model organism used for a variety of applications. These freshwater crustaceans are prime candidates for toxicity monitoring and have recently gained momentum as model organisms for understanding biological pathways while introduced to various pharmaceuticals. Daphnia have been used for these studies because of their ease of use, small nature, short lifespan, ability to asexually reproduce, and their transparency, which allows for relatively easy analysis using microscopy. While microscopy is a useful tool to examine a qualitative difference in the organism, researchers are limited when trying to quantitatively understand the differences between the samples. We show that a vibrating tube sensor can offer developmental insights of a model organism by monitoring its physical properties like mass, volume, and density. For these types of measurements, a glass tube vibrates at its natural resonance frequency, which is a function of the glass tube. When a sample is introduced into the vibrating tube, the additional mass will inversely change the resonance frequency of the sensor, which can be calibrated to a buoyant mass. We can trap that object by pumping the object forwards and backwards, producing several buoyant mass measurements and a buoyant mass profile over time. Preliminary results show that the buoyant mass of Daphnia magna in water can range from 12 to 22 micrograms. While mass monitoring can be an indicator of development, the buoyant mass can change depending on many phycological changes. We hypothesize that measuring the density and volume of a model organism continuously can provide meaningful insights about the development of model organisms. In this work, we build a system capable of measuring the density of the object in real-time by measuring the object of interest in two fluids of different but known densities. From two buoyant mass measurements, the true mass (in vacuo), density, and volume of the Daphnia can be calculated using Archimedes principle. We accomplish this by building a vacuum driven fluidic circuit that can delivery two different fluids on demand. An initial fluid, typically water (density of 1.00 g/mL), is loaded into our sensor, the daphnia or any object will pass through the sensor, and a frequency change will be recorded. Once a frequency change is measured, the system will pump in a second fluid like heavy water (density of 1.10 g/mL), and a subsequent buoyant mass is measured. This data is postprocessed using a custom Python script that detects all the frequency changes and calculates the mass, volume, and density of the Daphnia over time. With this setup, we can introduce toxicants in solution and monitor the changes of the physical properties. We believe that this measurement technique can provide quantitative methods that microscopy cannot provide and that this system will allow us to gain insights into the growth and health of single model organisms which will open up interesting avenues of research that were not possible previously.