title: Selective immobilization and detection of DNA on biopolymer supports for the design of microarrays.
abstract: DNA immobilization for the manufacturing of microarrays requires sufficient probe density, low unspecific binding and high interaction efficiency with complementary strands that are detected from solutions. Many of these important parameters are affected by the surface chemistry and the blocking steps conducted during DNA spotting and hybridization. This work describes an alternative method to selectively immobilize probes and to detect DNA on biocompatible, hydrophilic cellulose coated supports with low unspecific binding, high selectivity and appropriate sensitivity. It takes advantage of a relatively selective adsorption of water soluble polysaccharides on a solid cellulose matrix. Single strands of DNA were conjugated to this soluble polysaccharide and subsequently micro-spotted on solid cellulose thin films that were coated on glass and polymer slides. This resulted in adsorptively bound DNA-probes that were used to detect complementary, labelled DNA strands with different lengths and sequences by hybridization. The interaction of the DNA-conjugates with cellulose surfaces and the selectivity of hybridization were investigated by a quartz crystal microbalance with dissipation monitoring (QCM-D) and fluorescence scanning. The method of non-covalent immobilization of DNA probes on an uncharged, non-reactive, hydrophilic support lowers the unspecific binding and the number of handling steps required to conduct the experiments for the detection of DNA on microarrays. Simultaneously selectivity, hybridization efficiency and detection limits are maintained.
authors.affiliation: Laboratory for Characterization and Processing of Polymers, University of Maribor, Smetanova ulica 17, 2000 Maribor, Slovenia. Electronic address: rupert.kargl@um.si.
authors.forename: R
authors.initials: R
authors.lastname: Kargl
authors.affiliation: Institute of Chemistry, University of Graz, Heinrichstraße 28/3, 8010 Graz, Austria.
authors.forename: V
authors.initials: V
authors.lastname: Vorraber
authors.affiliation: Institute of Chemistry, University of Graz, Heinrichstraße 28/3, 8010 Graz, Austria.
authors.forename: V
authors.initials: V
authors.lastname: Ribitsch
authors.affiliation: Materials, Sensor Systems, Institute for Surface Technologies and Photonics, Joanneum Research, Franz-Pichler-Straße 30, 8160 Weiz, Austria.
authors.forename: S
authors.initials: S
authors.lastname: Köstler
authors.affiliation: Laboratory for Characterization and Processing of Polymers, University of Maribor, Smetanova ulica 17, 2000 Maribor, Slovenia.
authors.forename: K
authors.initials: K
authors.lastname: Stana-Kleinschek
authors.affiliation: Institute of Chemistry, University of Graz, Heinrichstraße 28/3, 8010 Graz, Austria.
authors.forename: T
authors.initials: T
authors.lastname: Mohan
mesh_terms: D001483:Base Sequence; D001704:Biopolymers / Q000737:chemistry*; D015374:Biosensing Techniques; D004247:DNA / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification*; D015342:DNA Probes / Q000737:chemistry / Q000235:genetics; D018076:DNA, Complementary / Q000737:chemistry; D009693:Nucleic Acid Hybridization; D020411:Oligonucleotide Array Sequence Analysis / Q000379:methods*; D020349:Surface Plasmon Resonance
chemical_list: D001704:Biopolymers; D015342:DNA Probes; D018076:DNA, Complementary; D004247:DNA
keywords: Adsorption; DNA-immobilization; DNA-microarrays; Fluorescence detection; Hybridization; Quartz crystal microbalance