Presented here is a method for preparing small DNA arrays on aldehyde-bearing glass slides. Immobilization involves reductive amination and employs oligonucleotides with 3¢-terminal lysine residues, obtained in high yield from solid phase syntheses. Spot patterns are produced by protecting selected areas of the aldehyde slides with wax, coating the free surface with a methyl triethylene glycol derivative, and removing the wax with dichloromethane. The DNA arrays give better signal to noise ratios in hybridization experiments than slides without passified background.

Color reveals base: The enzymatic template‐directed elongation of primers with fluorophore‐labeled nucleoside triphosphates is the most frequently used reaction for determining DNA sequences. Primer extension followed by optical read out can now be achieved without enzymes.

Farbe zeigt Kernbase an: Die enzymatische templatgesteuerte Verlängerung von Primern mit fluorophormarkierten Nucleosidtriphosphaten ist die am häufigsten für die Bestimmung von DNA‐Sequenzen eingesetzte Reaktion. Nun ist die Primerverlängerung mit anschließendem optischem Auslesen ohne Enzyme möglich.

No abstract

Oligonucleotides with a 3'-terminal 5-alkynyl-3'-amino-2',3'-dideoxyuridine residue were prepared, starting from 2'-deoxyuridine. The optimized route employs a 2',3'-dideoxy-3'-trifluoroacetamido-5-iodouridine 5'-phosphoramidite as building block for DNA synthesis and involves on-support Sonogashira coupling with N-tritylpropargylamine to generate oligonucleotides. The amino group of the propargylamine side chain was acylated to accelerate primer extension reactions involving the 3'-amino group. Three acyl groups were identified that decrease the half-life for DNA-templated extension steps with 7-azabenzotriazole esters of 2'-deoxynucleotides. The residue of 4-pyrenylbutyric acid was found to accelerate primer extension reactions and to render them more selective than those of the control primer. With this substituent, primer extension is also faster than previously measured for three-strand systems involving template, aminoprimer, and a downstream-binding helper oligonucleotide. Fast-reacting primers might become useful for genotyping single nucleotides.