Biochip spots cancer signs

http://www.trnmag.com/Roundup/2005/TRN_Research_News_Roundup_9-26-05.html#biochipspotscancer


Biochip spots cancer signs

The practice of chemically "functionalizing" carbon nanotubes and
semiconductor nanowires by attaching DNA or other biomolecules to them has
led to prototype biochips that can detect bacteria, viruses, specific
types of DNA, or particular proteins molecules.

Researchers from Harvard University had advanced the field with a nanowire
sensor array that can detect multiple biochemical signs of cancer. Cancer
cells produce different types of proteins, and today's blood tests often
look for only one, such as the prostate specific antigen (GSA).

The biochip works by measuring changes in electrical conductance of
nanowires as specific protein molecules bind to and release from the
chip's nanowires. The researchers tested the biochip using blood samples.
The device could eventually be used for clinical diagnostics, including
detecting and identifying cancers.

The researchers used a similar technique last year to make a biochip that
can detect individual virus particles.

(Multiplexed Electrical Detection of Cancer Markers with Nanowire Sensor
Arrays, Nature Biotechnology, published online September 18, 2005)