The continuously increasing degree of miniaturization of electronic circuits and the devel￾opment of corresponding fabrication technologies stimulated progress also in other fields,
such as analytical chemistry. The ideas of “labs-on-chips,” in which all manual procedures
required to obtain an analytical result are automatically performed on a chip, were pre￾sented almost 20 years ago, and fabrication technologies for DNA chips, which allowed
to obtain genetic information in a highly parallel manner, were suggested already in the
beginning of the nineties. These early dreams of miniaturized highly integrated analyti￾cal devices were based on the combination of developments in very different fields. The
development and industrial fabrication of integrated electronic circuits had shown that
by photolithography silica and glass could be precisely structured in all three dimensions
on the micrometer or even nanometer scale. In biology, amplification methods such as
the polymerase chain reactions (PCR), gene sequencing technologies, and biotechnologi￾cal production methods for proteins were established. In organic chemistry, methods of
combinatorial solid phase synthesis were developed, which made peptides and oligonu￾cleotides easily accessible, and analytical separation methods were developed in which
columns or planar surfaces were replaced by capillaries, such as in capillary electrophoresis
or gas chromatography. This was accompanied by improvements in detectors, which had
to deal with lower amounts of analyte molecules, a side effect of miniaturization.