18 Biotechnology
➠
Manchester say they have found a reliable new way of example, a pin-prick-size droplet of blood, and within an
attaching active proteins to a chip. hour provide a DNA analysis.
Biological chemists have engineered modified proteins “In creating these automated micro-fluidic devices, we
with a special tag, which makes the protein attach to a can now begin to do macro-chemistry at the microscale,”
surface in a highly specified way and ensures it remains Landers said.
functional. Such a device could be used in a doctor’s office,
The attachment occurs in a single step in just a few for example, to quickly test for an array of infectious
hours – unlike with existing techniques – and requires no diseases, such as anthrax, avian flu or HIV, as well as for
prior chemical modification of the protein of interest or cancer or genetic defects.
additional chemical steps. Because of the quick turn-around time, a patient
would be able to wait only a short time on-site for a
DNA chips
diagnosis. Appropriate treatment, if needed, could begin
DNA chips have revolutionised biological and medical immediately.
science. For many years scientists have tried to develop Currently, test tube-size fluid samples are sent to
similar protein chips but technical difficulties associated external labs for analysis, usually requiring a 24- to
with attaching large numbers of proteins to surfaces have 48-hour wait for a result.
prevented their widespread application. “Time is of the essence when dealing with an
“The method we have developed could have profound infectious disease such as meningitis,” Landers said. “We
applications in the diagnosis of disease, screening of new can greatly reduce that test time, and reduce the anxiety
drugs and in the detection of bacteria, pollutants, toxins a patient experiences while waiting.”
and other molecules,” says Micklefield.
Researchers from Manchester are currently working
A lab-on-a-bead
as part of a consortium of several universities on a Researchers at Wake Forest University in North Carolina,
£3.1 million project which is aiming to develop so-called USA are using nanotechnology to search for new
nanoarrays. These would be much smaller than existing cancer-fighting drugs through a process that could be up
micro arrays and would allow thousands more protein to 10 000 times faster than current methods.
samples to be placed on a single chip, reducing cost The Lab-on-Bead process will screen millions of
and vastly increasing the volume of data that could be chemicals simultaneously using tiny plastic beads so
simultaneously collected. small that 1000 of them would fit across a human hair.
Each bead carries a separate chemical, which can be
Microsizing genetic testing
identified later if it displays the properties needed to
Using new lab-on-a-chip technology, James Landers treat cancer cells. One batch of nanoscopic beads can
hopes to create a hand-held device that may eventually replace the work of thousands of conventional, repetitive
allow physicians, crime scene investigators, laboratory tests.
pharmacists, even the general public to quickly and “This process allows the beads to do the work for
inexpensively conduct DNA tests from almost anywhere, you,” explains Jed Macosko, project director and assistant
without need for a complex and expensive central professor of physics at Wake Forest. “By working at
laboratory. this scale, we will be able to screen more than a billion
“We are simplifying and miniaturising the analytical possible drug candidates per day as opposed to the
processes so we can do this work in the field, away from current limit of hundreds of thousands per day.”
traditional laboratories, with very fast analysis times, Other members of the research team at Wake Forest
and at a greatly reduced cost,” said Landers, a University include co-principal investigator Martin Guthold,
of Virginia professor of chemistry and mechanical an associate professor of physics, and Keith Bonin,
engineering and associate professor of pathology. department chair and professor of physics.
Landers published a review in October of his research
and the emerging field of lab-on-a-chip technology in the
Parallel processing
journal Analytical Chemistry. Macosko said the team and their collaborators at the
“This area of research has matured enough during the University of Waterloo in Ontario, Canada, are developing
last five years to allow us to seriously consider a device that will automate the Lab-on-Bead process
future possibilities for devices that would allow sample- and permit parallel processing to attain faster screening
in, answer-out capabilities from almost anywhere,” he results.
said. The Wake Forest researchers are also working with
Landers and a team of researchers, including biotechnologists at Harvard University in Boston and
mechanical and electrical engineers, with input from Université Louis Pasteur in Strasbourg, France, which
pathologists and physicians, are designing a hand-held are providing the chemicals being screened for drug
device – based on a unit the size of a microscope slide candidates.
– that houses many of the analytical tools of an entire Biotech company NanoMedica has already shown
laboratory, in extreme miniature. The unit can test, for interest in commercialising the process. u
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