title: Peptide-tags for enhanced DNA microarray performance.
abstract: DNA microarrays are powerful tools for gene expression analysis and genotyping studies in research and diagnostic applications. A high sensitivity and short time-to-result are prerequisites for their practical application in the clinic. The hybridization efficiency of DNA microarrays depends on the probe density and the probe orientation and thus their accessibility for target molecules. In order to find an optimal probe immobilization procedure a set of different oligonucleotide modifications was tested on epoxy silane functionalized glass slides. It was found that histidine-tagged oligonucleotides resulted in the highest amount of bound probe and by far the best hybridization efficiencies. The detection limit obtained with histidine-tagged probes was up to two orders of magnitude lower compared to commonly used probe modifications. In order to further investigate the binding mechanism of histidine-tags towards functionalized glass substrates a set of different peptide-tags with and without free terminal amino-groups and with different amino acid compositions was tested. The results indicate an impact of the terminal amino group on the covalent surface binding and of aromatic amino acid residues on the enhanced hybridisation efficiency.
authors.affiliation: Division of Pathway Medicine, College of Medicine and Veterinary Medicine, The University of Edinburgh, Chancellor's Building, 49 Little France Crescent, Edinburgh, EH16 4SB, Scotland. holger.schulze@ed.ac.uk
authors.forename: Holger
authors.initials: H
authors.lastname: Schulze
authors.forename: Alan J
authors.initials: AJ
authors.lastname: Ross
authors.forename: Stuart W J
authors.initials: SW
authors.lastname: Ember
authors.forename: Julie
authors.initials: J
authors.lastname: Luby
authors.forename: Mizanur
authors.initials: M
authors.lastname: Khondoker
authors.forename: Gerard
authors.initials: G
authors.lastname: Giraud
authors.forename: Ilenia
authors.initials: I
authors.lastname: Ciani
authors.forename: Chaker
authors.initials: C
authors.lastname: Tlili
authors.forename: Davide
authors.initials: D
authors.lastname: Papale
authors.forename: Jonathan G
authors.initials: JG
authors.lastname: Terry
authors.forename: Andrew R
authors.initials: AR
authors.lastname: Mount
authors.forename: Anthony J
authors.initials: AJ
authors.lastname: Walton
authors.forename: Jason
authors.initials: J
authors.lastname: Crain
authors.forename: Peter
authors.initials: P
authors.lastname: Ghazal
authors.forename: Till T
authors.initials: TT
authors.lastname: Bachmann
authors.forename: Colin J
authors.initials: CJ
authors.lastname: Campbell
mesh_terms: D016174:Hepacivirus / Q000235:genetics*; D019698:Hepatitis C, Chronic / Q000821:virology*; D006639:Histidine / Q000737:chemistry*; D006801:Humans; D009693:Nucleic Acid Hybridization / Q000235:genetics / Q000379:methods*; D020411:Oligonucleotide Array Sequence Analysis / Q000379:methods*; D015345:Oligonucleotide Probes / Q000737:chemistry*; D009842:Oligopeptides / Q000737:chemistry*
chemical_list: C471213:His-His-His-His-His-His; D015345:Oligonucleotide Probes; D009842:Oligopeptides; D006639:Histidine