Journal: Analytical Chemistry

Article Title: Nonaqueous Oxidation in DNA Microarray Synthesis Improves the Oligonucleotide Quality and Preserves Surface Integrity on Gold and Indium Tin Oxide Substrates

doi: 10.1021/acs.analchem.3c04166

Figure Lengend Snippet: (top) Resistance of gold- and ITO-coated microscope slides before and after DNA synthesis under iodine or CSO-mediated oxidation conditions. Measurements were taken with an ohmmeter at three diagonally opposed locations (bottom): slide corners (green), within the reaction chamber (red), and within the MAS synthesis area (blue). Sheet resistance (in Ω/square) was estimated by dividing the resistance with the length/width ratio of the rectangle encasing the two measurement points. The ratio was ∼3:1 for the slide dimensions, 2:1 for the reaction chamber, and 1.4:1 for the synthesis area. The sheet resistance and electrical resistance should be understood as approximate values only with an error margin of at least ±10% across three independent measurements.

Article Snippet: Microarray synthesis was carried out on glass microscope slides (Schott Nexterion D) silane-functionalized with N -(3-triethoxysilylpropyl)-4-hydroxybutyramide (Gelest SIT8189.5), gold-coated microscope slides with a 3D-amine layer (PolyAn 109 10008), or ITO-coated SuperEpoxy 2 microscope slides (ArrayIt).

Techniques: Microscopy, DNA Synthesis

Journal: Analytical Chemistry

Article Title: Nonaqueous Oxidation in DNA Microarray Synthesis Improves the Oligonucleotide Quality and Preserves Surface Integrity on Gold and Indium Tin Oxide Substrates

doi: 10.1021/acs.analchem.3c04166

Figure Lengend Snippet: (A) Fluorescence signals with a Cy3-labeled complementary sequence hybridized onto 25mer DNA microarrays decorated with ∼2000 replicates of the same sequence. Synthesis was performed using either iodine/water (yellow bars) or CSO (blue bars) as the oxidizer and otherwise standard photolithographic conditions on gold- or ITO-coated microscope slides. The glass copy (gold/ITO) labeling refers to the signal from the glass slide when synthesized alongside a gold- or ITO-coated substrate. (B) The background signal is recorded from features that only contain a dT 5 linker. (C) The signal/background corresponds to the ratio between hybridization signal and background fluorescence. (D) The dual array ratio is the ratio between fluorescence signals on the conductive substrate and those of the glass microscope slide. Error bars are the SD. (E) In the dual-array MAS procedure, a second microarray is produced simultaneously on a common silanized glass slide (“glass copy”). (F) Excerpts of microarray scans after hybridization with a Cy3-labeled complementary 25mer DNA strand. Hybridization was performed on gold and ITO-coated microscope slides and their duplicate on silanized glass. Each feature is a matrix of 5 × 5 micromirrors with a one-mirror wide gap between adjacent features. Features are randomly distributed across the entire microarray, and all contain the same 25mer DNA sequence. Excerpts are ∼0.5% of the total synthesis area. The scale bar is ∼100 μm.

Article Snippet: Microarray synthesis was carried out on glass microscope slides (Schott Nexterion D) silane-functionalized with N -(3-triethoxysilylpropyl)-4-hydroxybutyramide (Gelest SIT8189.5), gold-coated microscope slides with a 3D-amine layer (PolyAn 109 10008), or ITO-coated SuperEpoxy 2 microscope slides (ArrayIt).

Techniques: Fluorescence, Labeling, Sequencing, Microscopy, Synthesized, Hybridization, Microarray, Produced