iGEM team members finalizing research before October competition. (L-R) Carlos Alvarado, Ellen Qin, Nisarg Patel, Ryan Muller
disease is the second-leading cause of death in children under five
years old—killing as many as 1.5 million children worldwide every year.
These startling statistics from the World Health Organization (2009)
point to the reason why a group of undergraduate students from Arizona
State University is working to develop a low-cost biosensor—a simple
device that would detect contaminated drinking water.
interdisciplinary team of nine students is participating in the 2012
International Genetically Engineered Machine (iGEM) competition—a
prestigious global event that challenges students to design and build
simple biological systems made from standard, interchangeable parts.
ASU team started its research during the summer to prepare for the
synthetic biology competition. Its goal is to create a user-friendly,
DNA-based biosensor that can detect major pathogens. The low-cost device
would be used in the field rather than in a laboratory.
are developing a biosensor that will detect pathogenic bacteria, such
as Shigella, Salmonella and E. coli, that cause diarrhea,” said Ryan
Muller, an undergraduate student in ASU’s School of Life Sciences and an
iGEM team leader. “Ideally, you would use our biosensor to check
different water supplies in third world-countries to determine whether
the water is safe to drink.”
The team is working on two biosensor designs.
first one targets DNA,” explained Nisarg Patel, a molecular biosciences
and biotechnology major in School of Life Sciences, as well as a
political science major. “Since each type of pathogen has different DNA,
we want to create complementary sequences—sequences that match a
specific DNA. We will take bacterial samples from the water, pull out
the DNA and check whether it complements our DNA probe. If it does, it
will produce a color response and then we’ll know that the water is
for portability, Patel said the second design tests the membranes of
bacteria. When using the device to test water, if certain proteins
attach to a bacterial membrane, the sample will turn blue—indicating the
water is contaminated with a pathogen and would not be safe to drink.
advantage of this design over previous designs in the field lies in the
cheap production of probes and the enzymatic chain reaction,” said
Abhinav Markus, a biomedical engineering student in ASU’s Ira A Fulton
Schools of Engineering. “Samples can be tested in the field with minimal
cost and high sensitivity.”
the ASU iGEM team first met this summer, Madeline Sands, an
anthropology major in the university’s School of Human Evolution and
Social Change, pitched the idea to build a low-cost biosensor. Sands
previously traveled to Guatemala as part of an ASU field experience.
There, she conducted community health research under the direction of
Jonathan Maupin, a medical anthropologist. Sands realized that
contaminated water presents a serious health problem for developing
constant earthquakes, landslides and rains in Guatemala, it can often
be difficult to determine if a water source is contaminated,” said
Sands. “My time there made it clear that having a way to detect
contaminated water could lead to a further reduction in the incidence
and morbidity of diarrhea.”
October, the team will present its device during the iGEM regional
competition at Stanford University. If successful, they will move on to
the global competition in November at Massachusetts Institute of
ASU iGEM team members include: Rohit Rajan, Ethan Ward, Hyder Hussain,
Amanda Ispas and Ellen Qin. Kylie Standage-Beier, a biological sciences
major and previous iGEM team member, serves as an advisor.
State University iGEM team sponsors include School of Life Sciences;
Barrett, The Honors College; Ira A. Fulton Schools of Engineering;
School of Biological Health Systems and Engineering; College of Liberal
Arts and Sciences; School of Politics and Global Studies; and
Departments of Chemistry and Biochemistry.
Source: Arizona State University