A team of scientists from The University of Texas at Arlington and MIT has figured out how to quantitatively observe
cellular processes taking place on so-called “lab on a chip” devices in a
The new technology will be
useful in drug development as well as disease diagnosis, researchers say.
In a paper published in Nature’s
online journal Scientific
Reports, the team said it overcame past limitations on quantitative
microscopy through an opaque media by working with a new combination of near
infrared light and a technique called quantitative phase imaging. Quantitative
phase imaging is about a decade old. It uses shifts in phases of light, not
staining techniques, to aid specimen imaging – earning the term “label-free.”
“To the best of our knowledge, this is the
first demonstration of quantitative phase imaging of cellular structure and
function in silicon environment,” said Assistant Professor of Physics
Samarendra Mohanty, head of the Biophysics and Physiology Laboratory at UT
Arlington and corresponding author on the paper.
The UT Arlington/MIT team was
able to prove success in analyzing specimens through a silicon wafer in two
instances. In one, they accomplished full-field imaging of the features of red
blood cells to nanometer thickness accuracy. In another, they observed dynamic
variation of human embryonic kidney cells in response to change in salt
concentration. Mohanty believes that his group’s current work on near infrared quantitative
phase imaging can lead to non-invasive, label-free monitoring of neuronal activities.
Additional co-authors include: Bipin
Joshi and Nelson Cardenas, of UT Arlington; and Ishan Barman, Narahara Chari
Dingari, Jaqueline S. Soares and Ramachandra R. Dasari, all of MIT.
“Silicon-based micro devices
known as labs-on-a-chip are revolutionizing high throughput analysis of cells
and molecules for disease diagnosis and screening of drug effects. However,
very little progress has been made in the optical characterization of samples
in these systems,” said Joshi, a recent graduate and lead author on the
paper. “The technology we’ve developed
is well-suited to meet this need.”
Barman, now an assistant
professor at Johns Hopkins University, said the new paper is a prime example of
the type of research he hopes to do - projects pulled by needs of the
biomedical community and continually pushing the edge of biophotonic solutions.
“We envision that this significantly expands
the visualization possible in silicon based microelectronic and micromechanical
devices,” he said.
The new paper is called
“Label-free route to rapid, nanoscale characterization of cellular structure
and dynamics through opaque media.” It is available online here: http://www.nature.com/srep/2013/131002/srep02822/full/srep02822.html.
Mohanty’s group has recently
combined the near infrared quantitative phase imaging with near-infrared
optical tweezers for tomographic imaging of cells [N.
Cardenas, and S. K. Mohanty, “Optical tweezers assisted quantitative phase
imaging led to thickness mapping of red blood cells”, Appl. Phys.
Lett., 103, 013703 (2013)].
The joint UT Arlington/ MIT research
was supported by Nanoscope Technologies and funded in part by a National Institute of Biomedical Imaging
and Bioengineering grant.
The University of Texas at Arlington is a comprehensive
institution of about 33,000 students and more than 2,200 faculty members in the
heart of North Texas. It is the second largest school in The University of
Texas System. Visit www.uta.edu to learn more.