[Preparation and application of gel chip].

A new method for manufacturing three-dimensional gel film-coated chips was described in this paper and its advantages were evaluated by its application. A patch of polyacrylamide gel (15mm x 15mm x 20 microm) was fixed on the glass surface with Bind-Silane treatment, then activated by glutaraldehyde. The aldehyde groups in gel provided reactive sites that allowed covalent immobilization of molecules containing amino groups. Oligonucleotides were mechanically spotted by GMS 417 Arrayer. After hybridization with Cy-3 labeled probes, fluorescence signals of perfect binding can be discriminated from mismatched ones. Compared with two-dimensional glass chip, the capacity of oligonucleotides immobilized on gel film-coated chip is over 100 times. And the gel film-coated chip have lower background and shorter hybridization time. Monoclonal antibodys of cytokine IL-4, IL-5, IL-6, IL-7, ANG, I-309 and VEGF were also immobilized on the gel film-coated chips to make protein microarrays. After incubation with serum of breast cancer patients or normal persons, the microarray reacted with biotin-labeled second antibodys of cytokines and Cy-3-labeled streptavidin sequentially. Results show IL-4, IL-5, I-309 and VEGF of patients have higher expression level than normal persons. This kind of protein microarrays can be potentially helpful to clinical diagnosis. Furthermore different oligonucleotides or proteins can be performed in parallel in a single reaction with minimal amount of binding reagents. Such gel film-coated chips can be used widely in the fabrication of oligonucleotides and proteins microarrays.