title: Hydrazide oligonucleotides: new chemical modification for chip array attachment and conjugation.
abstract: We report the synthesis of new phosphoramidite building blocks and their use for the modification of oligonucleotides with hydrazides. The reaction of these hydrazide oligonucleotides with active esters and aldehydes is demonstrated for solution conjugation and immobilization. Compared with the established amino modified oligonucleotides, hydrazides show enhanced reactivity at neutral and acidic buffer conditions. One method to introduce hydrazides is using amidites with preformed, protected hydrazides. A completely novel approach is the generation of the hydrazide functionality during the oligonucleotide cleavage and deprotection with hydrazine. Therefore, building blocks for the introduction of esters as hydrazide precursors are described. For the enhanced attachment on surfaces branched modifier amidites, which introduce up to four reactive groups to the oligonucleotide, are applied. The efficiency of branched hydrazide oligonucleotides compared with standard amino modified oligonucleotides for the immobilization of DNA on active electronic Nanogen chips is demonstrated.
authors.affiliation: Nanogen Recognomics GmbH, Industriepark Höchst G830, 65926 Frankfurt am Main, Germany and. Nanogen Inc., 10398 Pacific Center Court, San Diego, CA 92121, USA.
authors.forename: Stefan
authors.initials: S
authors.lastname: Raddatz
authors.forename: Jochen
authors.initials: J
authors.lastname: Mueller-Ibeler
authors.forename: Joachim
authors.initials: J
authors.lastname: Kluge
authors.forename: Ludger
authors.initials: L
authors.lastname: Wäss
authors.forename: Gerhard
authors.initials: G
authors.lastname: Burdinski
authors.forename: John R
authors.initials: JR
authors.lastname: Havens
authors.forename: Tom J
authors.initials: TJ
authors.lastname: Onofrey
authors.forename: Daguang
authors.initials: D
authors.lastname: Wang
authors.forename: Markus
authors.initials: M
authors.lastname: Schweitzer
mesh_terms: D000447:Aldehydes / Q000737:chemistry; D002021:Buffers; D002851:Chromatography, High Pressure Liquid; D004952:Esters / Q000737:chemistry; D006834:Hydrazines / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D015394:Molecular Structure; D020411:Oligonucleotide Array Sequence Analysis / Q000295:instrumentation* / Q000379:methods*; D009841:Oligonucleotides / Q000138:chemical synthesis / Q000737:chemistry* / Q000378:metabolism*; D016133:Polymerase Chain Reaction
chemical_list: D000447:Aldehydes; D002021:Buffers; D004952:Esters; D006834:Hydrazines; D009841:Oligonucleotides