Kelly O’Quinn
Dr. Adam Melvin
Harmful Algal Blooms (HAB)-on-a-chip: Development of a
microfluidic platform to study algal chemotaxis
CHE 4221, Spring 2014
Project Summary
Harmful algal blooms (HABs) are caused by an overabundance of microscopic algae and
can have detrimental impacts on the ecosystem, the economy, and most importantly, human
health. Accumulated algae begin releasing toxins to kill or ward off predators, but in massive
quantities, brevetoxins are produced in much higher concentrations. Sometimes fish are exposed
to the toxins in low enough amounts that they survive, but still carry the toxin in their bodies.
When fish become poisoned by these algal toxins they have the potential to kill any predator that
consumes them, including humans. Aerosolized toxins, when inhaled by humans, lead to
respiratory illnesses. HABs mainly affect the coastal ecosystem and the people living there.
However, every region of the world has some type of coast, along an ocean or a lake that can be
affected by HABs.
This overabundance of algae can be attributed to both migration and reproduction of
algae, which both play a large role in causing harmful algal blooms. The main forces that induce
algal migration are still unknown. Algae migration happens for a variety of reasons. They
typically travel upward during the day in response to light for carbon fixation and travel back
down toward the ocean floor at night for nutrient consumption. This is called diel vertical
migration. However, the algae also migrate at different times and in response to different stimuli.
This project aims to study the migration of algae to better understand the patterns and underlying
causes of HABs.
Very little research on algae migration has been done on this scale to examine
interactions between algae and other environmental factors. Some experiments have been done
using homogeneous tanks, which lack dynamic control, to test algal migration, but few focusing
on the single-cell migration patterns and interactions between algae and nutrients. This allows for
precise spatial and temporal control of the system. Additionally, past experiments have failed to
provide environments similar to those found in the ocean, e.g. gradients of nutrients and
variations in temperature, salinity, and light.
By designing a microfluidic device, algal migration will be monitored due to the
influence of several environmental conditions. Different types of nitrogen-based nutrients
(nitrate, urea, and ammonia) will be added to the algae culture chamber of the device, and the
migration of algae in the migratory chamber will be monitored on the single cell level. Other
external variables like salinity, light, and temperature, will then be altered to evaluate algal
migration. By observing these migration patterns, which factors are most prominent in inducing
algae migration can be determined. After determining these factors, we will be able to prevent
future HABs from occurring.
The first objective of the project is to design and develop the microfluidic device. It will
be designed in AutoCAD and fabricated using techniques of soft lithography. The next objective
will be to characterize the new device to ensure it develops stable and well controlled gradients.
This will be accomplished using fluorescent tracers. The last objective will be to observe and
analyze algal migration in response to varied environmental conditions such as changes in
temperature, salinity, light, nutrient concentrations, and types of nutrients.
Background
Harmful algal blooms (HABs) are caused by an overabundance of microscopic algae
accumulated at the surface of the water. These blooms occur mainly in coastal ecosystems and
can have detrimental impacts on the ecosystem, the economy, and human health.1 Several factors
contribute to an overabundance of algae, including algal reproduction and migration. One of
species of algae that causes harmful algal blooms is the dinoflagellate Karenia brevis. This
species is responsible for the Red Tides in the Gulf of Mexico.2 K. Brevis is very well adapted to
its environment and can survive in nutrient-poor coastal areas.3 Until recently, people thought
blooms were caused simply by a rapid multiplication of algae. Sometimes, blooms occur too
quickly to be attributed solely to the reproduction of algae.4 It is now hypothesized that blooms
are caused partly by the migration of algae to the water surface. Algal migration is a combination
of many factors. However, there is a lack of understanding of what most prominently induces the
algae to migrate and thus contribute to HAB occurrence.
When HABs occur, they can cause harmful impacts on the ecosystem, surrounding
organisms, and the economy. Accumulated K. Brevis will begin releasing brevetoxins (a
neurotoxin), to kill or ward off predators; but when a massive population of the algae
congregates, the toxins are released in much higher concentrations, leading to harmful
implications. This toxin is responsible
for neurotoxic shellfish poisoning
(NSP).3 Sometimes, fish are exposed
to the toxin in small enough quantities
that they survive but still carry the
toxin in their bodies. When fish
become poisoned by algal toxins, they
gain the potential to kill predators that
consume them, including humans.
Additionally, these toxic fish and fish
in the surrounding area cannot be sold,
damaging the fishing industry, and
thereby
the
local
economy.
Furthermore, aerosolized toxins, when
inhaled by humans, lead to respiratory
Figure 1: Algal migration in response to various external factors:
illnesses.
HABs
have
severe
temperature, salinity, nutrients, and light.
implications on the health of organisms
in surrounding coastal areas. Therefore, there is a need to determine how HABs occur and how
they can be stopped. Understanding the external forces that drive algae to migrate is a key factor
in understanding the underlying cause of harmful algal blooms.
K. Brevis are mixotrophic organisms, obtaining energy both from photosynthesis and
organic nutrient consumption. Thus, they are both heterotrophic and autotrophic. These algae use
their flagella to swim through the water up to a speed of 1 m/hr. They are in constant motion
both in response to external factors as seen in Figure 1 and random motion when no stimulus is
present. This type of random motion is called a random walk. Chemotaxis is the movement of an
organism in response to a chemical stimulant. Algal cells can migrate using their flagella
allowing them to swim in
any
direction.
When
gradients are present, this
directs the movement of the
cells rather than swimming
randomly as shown in
Figure 3. Cells move toward
attractants, and away from
repellants in chemotaxis.
Algae cells make two major
migrations daily as shown in
Figure 2. This is called diel
vertical migration. Algal
Figure 2: Diel vertical migration. Algae swim upwards toward the light source during
migration upward during the
the day (phototaxis), and downward toward the nutrient source at night (chemotaxis).
day toward the sun for
carbon fixation is called phototaxis. This is similar to chemotaxis but the motion is a response to
light rather than to a gradient of nutrients. Migration downward at night toward nutrients on the
ocean floor is a chemotactic response to organic nutrients.5 The algae photosynthesize sunlight
during the day, and consume nitrogen and phosphorous based nutrients present on the ocean
floor at night. Algae migrate in response to many other factors as well, including temperature
and salinity gradients.6
In order to study how algae migrate in the ocean, a method to form an environment
similar to that found in the ocean is needed. This includes generating gradients of external
stimuli like those of nutrients and salinity. To do this, a technology must be developed that
allows for the study of algal migration by generating steady gradients. A technology capable of
producing and maintaining steady gradients has not yet been successfully designed and used.
Therefore, successful gradient generators are the next technology necessary for studying algal
chemotaxis. Gradients are important with respect to migration because the ocean is not a uniform
system;
ocean
water
contains
varying
concentrations of
nutrients, salinity,
temperature, and
light. In the past,
research on this
subject
was Figure 3: Cells placed in the center chamber will migrate in response to the attractant or repellent
conducted
using fed into the device. When no source is placed into the channel, the cells will exhibit a random walk
behavior.
homogeneous
tanks lacking dynamic control to observe algal migration patterns. Homogeneous tanks contain
fluids uniformly mixed throughout. However, the ocean is not a homogeneous system; it
contains gradients of light, temperature, and salinity, that all flux simultaneously. Therefore, it is
best to develop a new technology that will be capable of generating gradients that more
accurately replicate gradients found in the ocean. For the study of gradient-driven algal
migration, we will design, fabrication, and characterize a microfluidic device.
Microfluidic devices are beneficial for this type of research because it uses such a small
volume of fluid and allows for the spatial and temporal control of the system. In microfluidics,
the flow is laminar; therefore, all of the mixing of liquids occurs by diffusion in the channels.
Diffusion occurs when there is a concentration gradient, i.e. nutrients in a highly concentrated
area will move to an area of low nutrient concentration. Thus, a gradient of nitrogen-based
nutrients is generated and observations of how the algae move in response to the gradient can be
made. Microfluidics also allows for the single-cell tracking of the algal cells. Single-cell tracking
can be accomplished through the use of time-lapse imaging. This is important for understanding
of how the organism moves on an individual cell level. The exact rate the cells migrate can be
monitored by observing single cells of algae migrating. How sharp or intense the gradient is can
also affect the manner in which the cells move. The algae will move toward an attractant
(positive chemotaxis) and away from a repellant (negative chemotaxis) as seen in Figure 3.
Several types of microfluidic devices have been proposed for the study of cell chemotaxis;
however, these have been unable to generate steady, well-controlled, and consistent gradients.
These devices were difficult to make because of their complicated design or inability to create
stable gradients for long-term research.9 Microfluidic devices have been successfully used in
applications of screening for toxicity in marine microalgae and observing bacterial chemotaxis.7,8
They have also been successfully implemented in the study of Escherichia Coli chemotaxic
response to an attractant, α-methyl-DLaspartate. Cheng et al developed a
diffusion-based
device
capable
of
producing steady gradients to observe the
E. Coli migration. 9
Research Objectives
Although we know algal migration
occurs, the factors and variables that are
most prominent in causing algae to migrate
and thus cause harmful algal blooms are
Figure 4: Three-channel device. Cells will be placed in the center
unknown. The goal of this project is to
channel, the top channel will be loaded with a source solution
(nutrients) and bottom channel containing the buffer solution.
determine the way in which algae migrate
and which external conditions (nitrogenbased nutrients, salinity, temperature, and light) most strongly impact that migration.
Our first objective will be to design, fabricate, and characterize a microfluidic device
capable of studying algae migration as shown in Figure 4. This device will create the gradients of
nutrients needed to observe migration toward the high concentration of nutrients. We will create
a three-channel device with a flow-free center channel. The cells will be placed into this channel.
It is important that the center channel is flow-free because flow is a variable that affects the
motility of free-swimming algae cells. The flow could cause a temporary variation in the
gradients, causing an inconsistency in the measurements.10 It will be certain that the migration
occurs by cell chemotaxis rather than forced flow movements. A benefit of using flow-based
gradient generators is that the gradient can be developed
very quickly. However, it is difficult to separate the flow
movement of algae from the gradient directed migration
of algae.9 The top channel of our device will contain the
source, and the bottom channel, a buffer solution. In the
device, the gradient will be generated across the top and
the bottom channels and the cells placed in the center
flow-free channel will be able to migrate toward or away
from the gradient. The nutrients will diffuse through the
channels to the buffer channel. The device will be
designed in AutoCAD and fabricated using soft
lithography. We will then characterize the new device to
Figure 5: Previous work showing the tracers as a
ensure it develops stable and well controlled gradients.
generated gradient in the device. These
This will be accomplished using fluorescent tracers. The
fluorescent tracers are visible under UV light,
tracers will be visible under UV light, so we will be able
making them useful for tracking gradient
formation.
to observe the tracer creating the gradients we are
looking for as shown in Figure 5. This figure shows the
gradient of the tracer forming in the device. Lastly, we will observe and analyze algal migration
in response to different nitrogen-based nutrient gradients. These nutrients will include nitrate,
urea, and ammonia. This research will also include the study of other varied environmental
conditions including temperature, salinity, and light. By altering the salinity of the buffer
solution, we can observe how the algae cells migrate in response to gradients of salinity. These
are main gradients that are present in the ocean, and therefore need to be altered in these
experiments to understand algae migration patterns in the ocean. Then we will be able to
determine the most prominent forces or group of forces that cause harmful algal blooms to occur.
After obtaining the knowledge of which factors are most prominent in algae migration, we can
be better equipped to handle future harmful algal blooms and target the underlying problem of
algae migration.
Proposed Work
This project aims to study algal migration patterns and movements using a microfluidic device.
With this device, single cell movements of algae can be observed in order to precisely determine
migration patterns of algae and how they migrate with respect to different types of gradients.
This includes different nitrogen-based nutrients (ammonia, urea, nitrate) and variations in
intensity and steepness of the gradient.
Microfluidic devices were chosen for
this study because past techniques for
studying algal migration were not
effective at generating gradients. Other
devices lacked the ability to create
steady, well-controlled gradients. They
also were complicated in design and
lacked the ability to sustain these
generated gradients for long-term
study.11 This new technology allows for
Figure 6: A top view of the microfluidic device. The center channel is
precise dynamic control of the system
flow-free and will contain the algae cells. The top channel will contain the in order to effectively analyze cell
nutrient flow, and the bottom channel will contain the sink, or buffer,
migration with respect to gradients of
flow.
nitrogen-based nutrients like those
found in the ocean. The objectives of this project are 1. make the three-channel microfluidic
device, 2. characterize the device, 3. implement the device for study of algal migration.
Objective 1:
The first objective of this project is to design a threechannel microfluidic device in order to study algal migration
across gradients. The design of the device will be done using
AutoCAD. The channels will be 600μm wide and spaced 200μm
apart as shown in Figure 6. The channels will be 10 mm long and
50μm high. The source channel will be the top channel and the
sink channel will be the bottom channel. This design in AutoCAD
will cover the dimensions and placement in the x-y plane. The
migratory channel will be flow-free meaning there will not be
flow of cells in that channel. The cells will be placed in the
channel and allowed to migrate freely toward or away from the
gradient. This is an important design constraint because this will
ensure that the device is allowing the cells to migrate
chemotactically and not forcing migration from the flow in the
center channel.12 Using soft lithography techniques, the zdimension, or height, will be added to the channels. It is important Figure 7: Steps of fabricating
for the channels to be relatively low in height to eliminate a the 3 channel device.
potential bias of the cells migrating toward the light source. After
designing the device, it will be fabricated using soft lithography and polydimethylsiloxane
(PDMS) replication techniques as seen in Figure 7. PDMS has the advantage of low cost and
simplicity of creating new devices. It is a cheap material and all the devices are made with the
same mold with each replication. First, a silica wafer is spin coated with a photoresist (SU-8,
MicroChem) layer on top. SU-8 is a polymer that when exposed to UV light, the polymers crosslink, solidifying the material. With the device design placed on top, it will be exposed to UV
light then baked. The wafer will then be placed in SU-8 developer in which only the cross-linked
polymers remain and the SU-8 left on the wafer will dissolve in solution. PDMS will be poured
over the mold then peeled off. The holes will be punched all the way through the PDMS layer for
the inlet and outlet flow tubes to be inserted. The holes will be punched using the desired
thickness of tubing that will
be used to input the flow.
This PDMS layer will be
adhered to a 3% agarose
layer. The diffusion will
occur beneath the channels,
through the agarose, from the
source channel across the Figure 8: A side view of the device. The PDMS layer will be adhered to the agarose
cell channel to the sink layer then to the glass slide. The tubing will be inserted into each flow channel inlet
channel. The channels will and outlet location.
be loaded by inserting tubes into the channel openings and placing a loaded syringe into the tube
and injecting the source or buffer into the desired channel. By using a syringe pump, the flow
rate in each channel can be controlled. The cells will be injected the same way, but no flow will
be introduced into this channel. The orientation of the layers, channels, and tubes can be seen in
Figure 8. This process also has the benefit that new designs are easy to make. There is quick
turnaround if a new photomask design is needed. By designing a new device, a new photomask
can be obtained within a few days, and there will be a new mold to work with. This simplifies
the process of altering the design.
Objective 2:
The second objective is to characterize the
device using fluorescent tracers to observe the gradient
generation in the device. The red fluorescent dye,
rhodamine dextran will be used as a tracer to observe
the creation of the gradient across the channels. The
tracers absorbs light energy at one wavelength
(excitation) and emits is at a longer wavelength
(emission), making it visible with fluorescent
microscopy. In Figure 9, the red bar indicates a line
scan taken in Image J. Image J analyzes images by
correlating the intensity of the pixels with the
Figure 9: Previous work with a gradient generator
concentration of the gradient at each location. This
that still had flow bias in the migratory channels.
This shows a line scan in ImageJ. In the graph, the
characterization technique will be supplemented with
increase in intensity of fluorescence can be seen
models in COMSOL. With this software, boundary
shifting across the channels over time.
layers can be established and flow in the channels can
be detailed. COMSOL contains a microfluidic module
that will be used to model gradient generation in the channels.
Objective 3:
The third objective is implementing the device in studying algal migration in response to
different types of gradients. These include variations on types of nutrients, steepness, and
intensity. The first algal species studied will be the unicellular Chlamydomonas reinhardtii. This
species will be studied first because it is very easy to work with and there has been extensive
study about it. This species has a quick generation time and can survive in a variety of different
environments, thriving in both light and dark.13 Both flow channels of the device will be loaded
first. The gradient will take about an hour to develop, similar to that of the device used by Cheng
et al. After a steady gradient is formed, the algae will be loaded into the center, flow-free channel
while minimally disrupting the gradient. By observing the COMSOL models and the tracers’
movement over time, it is possible to track the generation of the gradient over time. Then, the
changes in the gradient over time will be tracked by mixing the tracers with the source so the
motion of the gradient can be visibly tracked. The source will be the nutrients in the channel, and
the cells will migrate toward this developed gradient of nutrients. Different types of nitrogenbased nutrients will be used as the source. The algal movement and gradient generation will be
compared every minute for about an hour using fluorescent microscopy with a red filter so the
cells are visible. The pigmentation in the cells allows them to be seen with a red filter. The cell
migration can be analyzed by assigning signaling vectors to the step the cell takes at each time
interval. The average of these vectors can be taken for correlation between different
experiments.14 After analyzing C. reinhardtii migration in the device, the process can be repeated
with K. Brevis because this is the species of interest. Since C. reinhardtii can survive in such a
wide range of conditions, it will likely migrate differently than K. Brevis, which has a smaller
range of acceptable survival conditions. Cell density to be loaded will be experimentally
determined, but it will likely be around 10,000 cells/mL. This number ensures that the cells are
not over crowded in the channel. The average algal velocity is about 278μm/s.15 Depending on
the velocity of the specific species in each condition, the length of each experimental run will be
determined.
An advantage of this device is dynamic control of the system. Dynamic control
encompasses spatial and temporal control. This is important to have in the system in order to
alter precise parameters in the device to examine the cells migrating in various situations. The
type of gradient (variations on intensity and steepness and altering type of nutrient) can be
changed during the experiment or the gradient can be removed completely. To stop the source
flow and allow the gradient to die down would remove the flow. To change the intensity of the
gradient, the starting concentration of the source flow can be altered, and to change the gradient
steepness, the flow rate can be altered. These experiments will be repeated at high and low
temperatures, high and low light intensities, and high and low salinities. The goal is to determine
the most prominent factors of these: salinity, temperature, light, nutrients that cause algal
migration in the ocean. This will be important in determining what the forces are that are most
likely to induce algal migration. Design of Experiment (DOE) can be implemented to analyze the
significance of different environmental factors and constraints of the device. Analysis of
Variance (ANOVA) can be used to examine the variance among or between groups of
experiments. To characterize migrating cells, chemotactic index and directional persistence will
be evaluated. Chemotactic index is the ratio of the movement of each cell in the direction of the
gradient to the total distance moved by the cell in a given time frame.16
During this research, several iterations of designs of the device may need to be tested
before finding the proper device for studying algal migration. The length of each channel and the
distance between each channel may need to be optimized for maximum algal migration
observation. Additionally, the technique to adhere the agarose layer to the PDMS layer may need
to be altered multiple times to get optimum results. There are several options to adhere the
PDMS layer to the agarose layer. This includes building a Plexiglas box that will apply enough
pressure to hold the two layers together. Another option involves sucking out the air inside the
channels, applying negative pressure which seals the layers together. Alternatively, other
materials beside PDMS may be used like a thiol-ene resin that is naturally more hydrophilic than
PDMS.17 Another option is treating the PDMS with silanes as an adhesive between the glass
slide and the PDMS. Additionally, a few factors must be determined experimentally, including
the cell density to load and the best way to add them to the channel without disrupting the
gradient much. The time intervals and time to develop the gradient will be experimentally
determined and validated with the model in COMSOL. Accomplishing these objectives will
provide us with the knowledge of which naturally occurring factors in the ocean are the ones
most responsible for causing algae to migrate and thereby cause HABs to form. This provides us
with the understanding of what forces will need to be controlled in order to stop HABs from
occurring.
Broader Impacts
The identification of the most prominent forces that cause algal chemotaxis will help in the
understanding of how HABs form and what can be done to stop them from occurring. Because
this project involves the development of a new technology, this three channel microfluidic device
can be used to advance the study in other fields since it can be used for applications of other cell
chemotaxis, not just algae. These types of devices have been implemented for use in E. Coli
migration observation in response to α-methyl-DL-aspartate.18 They have also been used to study
a foodborne pathogen’s migration in response to acetic acid, and shown that acetic acid can be
used as a microbial agent by the food industry.19 The scientific community will benefit from the
development of a flow free microfluidic device capable of developing steady gradients because it
allows for precise dynamic control. All cells migrate differently in different gradients; therefore,
this device can be altered to be specific to whatever type of cells is being studied. If this research
is successful, the common citizen would benefit from fewer occurrences of HABs, leading to less
likelihood of human illnesses caused by algal toxins or consuming toxic shellfish.
References
Donald M. Anderson, Allan D. Cembella, and Gustaaf M. Hallegraeff, “Progress in
Understanding Harmful Algal Blooms: Paradigm Shifts and New Technologies for Research,
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2
Karen A. Steidinger, “Historical perspective on Karenia brevis red tide research in the Gulf of
Mexico,” Harmful Algae, 8, 2009, 549–561
3
R. N. Bearon, D. Grünbaum, R. A. Cattolico, “Effects of salinity structure on swimming
behavior and harmful algal bloom formation in Heterosigma akashiwo, a toxic
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“Diel vertical migration thresholds of Karenia brevis (Dinophyceae),” Harmful Algae, 8, 2009,
692–698
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6
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9
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11
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Mingming Wu, “A hydrogel-based microfluidic device for the studies of directed cell
migration,” Lab Chip, 2007, 7, 763-769
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Nonlinear Steady Microfluidic Gradients,” Nano Lett. 2010, 10, 3379-3385
12
Merchant SS et al, “The Chlamydomonas genome reveals the evolution of key animal and
plant functions,” Science, 2007, 318, 245-50
13
Michael C. Weiger, Shoeb Ahmed, Erik S. Welf, Jason M. Haugh, “Directional Persistence of
Cell Migration Coincides with Stability of Asymmetric Intracellular Signaling,” Biophys. J.,
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14
15
Blake A. Schaeffer, Daniel Kamykowski, Geoff Sinclair, Laurie McKay, Edward J. Milligan,
“Diel vertical migration thresholds of Karenia brevis (Dinophyceae),” Harmful Algae, 8, 2009,
692–698
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Chemotaxing Fibroblasts, Both High-Fidelity and Weakly Biased Cell Movements Track the
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17
Christopher O. Bounds, Jagannath Upadhyay, Nicholas Totaro, Suman Thakuri, Leah Garber,
Michael Vincent, Zhaoyang Huang, Mateusz Hupert, and John A. Pojman, “Fabrication and
Characterization of Stable Hydrophilic Microfluidic Devices Prepared via the in Situ TertiaryAmine Catalyzed Michael Addition of Multifunctional Thiols to Multifunctional Acrylates,”
ACS Appl. Mater. Interfaces, 2013, 5, 1643−1655
18
Shing-Yi Cheng, Steven Heilman, Max Wasserman, Shivaun Archer, Michael L. Shuler and
Mingming Wu, “A hydrogel-based microfluidic device for the studies of directed cell
migration,” Lab Chip, 2007, 7, 763-769
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Kelly O’Quinn
EDUCATION
Louisiana State University (LSU), Baton Rouge, LA
May 2015
Bachelor of Science in Chemical Engineering
Cumulative GPA: 3.51
EXPERIENCE:
Undergraduate Lab Assistant, Dr. Michael Benton, LSU
January 2014 – present
Baton Rouge, LA
 Perform experiments involving genetic engineering of cyanobacteria for biofuel use
 Prepare media for yeast, conduct gel electrophoresis, perform polymerase chain
reaction (PCR)
Research Intern, Gulf of Mexico Research Initiative (GoMRI), LSU
Baton Rouge, LA
May 2013 – August 2013
 Presented research at end of summer symposium at Tulane University, New Orleans
 Worked side-by-side with chemical engineering graduate students
 Performed lab work testing a rapid screening process for PHA production in
cyanobacteria species
 Participated in science outreach activities for 1st through 5th graders
HONORS
Shell Oil Company Technical Scholarship, BASF Academic Excellence Scholarship, Gulf of
Mexico Research Initiative Grant, Academic Scholars Resident Award, Chancellor’s Student
Aide Job, Pegues Engineering Scholarship, Junior League Scholarship for Seniors, Tuition
Opportunity Program for Students (TOPS)
ACTIVITIES
Wesley Foundation Methodist Campus Ministry, Distinguished Communicator Candidate,
Society of Peer Mentors (Treasurer 2014), Engineers Without Borders-LSU, Engineering
Council (AIChE representative Fall 2013), Society of Women Engineers, American Institute of
Chemical Engineers (Treasurer 2014, car team member), Alpha Lambda Delta Honor Society,
Phi Eta Sigma Honor Society
Facilities and Equipment
Equipment present in the Melvin lab at LSU includes a photoresist spinner, and a UV exposure
system. If the spin coater is not working in this lab, the LSU CAMD microfabrication lab has a
Headway Research Photoresist Spinner.
The Benton lab at LSU includes a Forma Scientific incubator for culturing the algal cells
and a bench top VWR VistaVision inverted microscope for observing the fluorescent tracer
movement in the device.
AutoCAD, necessary for device design, and MATLAB, required for quantifying the
migrating algae, are both available for free use on LSU campus computers in Patrick F. Taylor
hall. Dr. Nandakumar, in the chemical engineering department at LSU, has a license to
COMSOL which is necessary for modeling the gradients in the device.