Background: DNA microarray technology provides an efficient method for the detection of multiple
gene polymorphisms at the same time. However, the combination of high number of measured
polymorphisms necessary to reach statistical significance with today's high cost for
a single measurements makes population-wide studies impossible.
Aim: The goal of our project was to develop a new method to reduce time and cost of the
DNA array measurements.
Methods and results: The basis of a new array is a glass-slide sized alcali-free silicium dioxide slide.
Here an Au coated chrome-dioxide base is fixed. Using photolythography we establish
200 um diameter electric pads on the coating artificial rosin insulation. To these
Au pads we deliver thiol-marked oligonucleotide sequences using a newly developed
automatic pipetting system. These sequences are bind to the Au via sulphide bridges.
The probe sequences are designed to detect various polymorphisms associated with gastrointestinal
diseases. DNA is isolated from gastrointestinal biopsy specimens with standard phenol-cholophorm
extraction and ethanol precipitation. The DNA samples are then electronically hybridized
to the firm probe DNA within a few minutes. Finally the detection is performed in
an automatic scanner using fluorescent labeling.
Conclusion: Our new method provides a fast and cost-efficient custom DNA array technology, thus
allowing the screening of large patient populations, and detection of even very small
effects of gene polymorphisms.
