BeschreibungOne of the main challenges for further development of biochip technology is the strength of signals produced by probe-target interaction, especially for low probe and target concentrations. This is expected to become an increasingly important issue as chip technology drifts to smaller high-density chips. The signal intensity mainly depends on the functionality of the chip surface, the immobilization capacity and the density of attachment and accessibility for the interacting molecules. Immobilization chemistries which fulfill these demands have been developed for DNA and protein chips: Reactive epoxy resin , porous poly(styrene-co-4-vinylbenzylthiocyanate) (PST-co-VBT)  and chitosan were used as functional matrices for covalent binding of biomolecules. PST-co-VBT was illuminated with 254 nm UV light to achieve the desired photoisomerization SCN-NCS and subsequent binding of amino-modified oligonucleotides or proteins. Chitosan was made mechanically stable by bifunctional crosslinkers and applied especially for protein immobilization. The developed surface chemistries were evaluated by model oligonucleotide-, DNA-, and protein assays. Important parameters of evaluation were immobilization capacity, signal-to-noise ratio and spot morphology. The optimum print buffer was a trade off between desired pH of the coupling reaction, surfactant concentration and surface tension. Quality control procedures were applied to compare the results from slides of different immobilization chemistry, experiments and charges.
|26 Okt. 2003
|Workshop on New Trends in Nucleic Acid Based Biosensors
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