"Lab-on-a-chip" may soon be possible
By Sid Perkins
UPI Science News
WEST LAFAYETTE, Ind., June 27 (UPI) -- New manufacturing techniques for
semiconductors may do for the chemistry lab what transistors did for the
radio in the 1960s.
Purdue University researcher Fred Reigner has developed a way to shrink
specialized instruments from the chemistry lab onto a computer chip,
reducing them in size from one thousand to one million times. A single
chip could contain dozens or hundreds of "laboratories," each capable of
carrying out complex chemical analyses.
The miniaturized labs-on-a-chip can be used to perform capillary
chromatography or capillary electrophoresis, which are chemical techniques
used to separate a mixture into its pure chemical components. These types
of separations are commonly used in clinical analyses of blood and tissue
samples and in medical and pharmaceutical research.
In standard chromatography, the solution to be separated is poured or
forced through a tube packed with materials that have varying attraction
for the different components of the solution. As the mixture flows through
the column, it is separated into a series of zones, each containing a pure
substance.
Reigner's miniature laboratories employ the same principle, but the
difference is in their size and in the way they are made. The channels and
microscopic "particles" are etched into the silicon, creating chemical
reaction vessels the size of a speck of dust and chromatography columns
the size of a human hair.
Reigner says accurate measurements can be made using only a fraction of a
drop of liquid, using volumes up to a million times smaller than that
necessary for standard chromatographs.
Reigner says a single chip containing 10 to 100 mini-labs can be
fabricated for about $400, as compared to the $15,000 required for
comparable full-scale laboratory equipment.
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