Immobilization of oligonucleotides on crosslinked poly(vinyl alcohol) for application in DNA chips

In biotechnological applications there is an enormeous growth in the development of new miniaturized devices to reduce timescales, cost and amounts of reagents and starting materials. DNA chips represent miniaturized analytical tools that allow the simultaneous detection of different targets for high throughput screening. They consist of a small size support on which DNA probes are in-situ synthezised or immobilized. We present protocols for the effective immobilization of pre-synthezised 16S rRNA oligonucleotides on crosslinked poly(vinyl alcohol) (PVA). The polymeric gel consists of poly(vinyl alcohol) (PVA) crosslinked with poly(allylamin chloride) (PALAM) and monochlortriazinyl-β-cyclodextrin (β-CD) at pH 4, 6.8, 8 and 9. Mechanical characterization of the gels show that the immobilization capacity increases with increasing pH and increasing crosslinking within the gel. We will demonstrate that the hybridization efficiency on PVA chips is superior over commercially available chips based on nylon, nitrocellulose and aminoalkylsilane.