Strategies in the Preparation of DNA Oligonucleotide Arrays for Diagnostic Applications

Abstract

This report emphasizes the interfacial chemistry that is required to ensure proper attachment of oligonucleotides onto the surface of microarrays. For example, strategies for the covalent attachment of pre-synthesized oligonucleotides to glass slides, gold films, polyacrylamide gel pads, polypyrrole films, and optical fibers are surveyed in an attempt to better define the parameters for optimal formation and detection of DNA hybrids. These parameters include among others, the nature and length of the linkers attaching oligonucleotides to the arrays, and the surface density of oligonucleotides required for unhindered hybridization with DNA targets. Sensitive detection methods such as the use of light-scattering techniques, molecular beacons, surface plasmon resonance, attenuated total internal reflection-FTIR, and the evanescent field excitation of fluorescence from surface-bound fluorophores have been developed to study the kinetics and specificity of hybridization events. Finally, the synthesis of oligonucleotides directly on glass surfaces and polypropylene sheets has been investigated to enable DNA sequencing by hybridization and achieve oligonucleotide densities of ca. 10(6) sequences per cm(2) on DNA chips.

A Highly Versatile Microscope Imaging Technology Platform for the Multiplex Real-Time Detection of Biomolecules and Autoimmune Antibodies

“…This image is analyzed to identify single microbeads. Because fluorescence intensities between microbeads vary significantly due to the differences in the encoding dye concentration, an edge-based detection algorithm is applied [17]. Microbeads can be identified unambiguously by their circular shape, because microbeads are nearly perfect spheres.…”

Assay for glucose oxidase from Aspergillus niger and Penicillium amagasakiense by Fourier transform infrared spectroscopy

“…Infrared (IR) spectroscopy is a highly sensitive and reproducible analytical technique which is based on the energy of molecular vibrations of several functional groups of organic compounds such as carbonyl, methyl, amide, and so on [12]. IR spectroscopy of biological macromolecules and entire cells or tissues is a scientific area of increasing importance, with several applications in biophysics, biochemistry, and medicine [13,14].…”

Microarray Technology as a Universal Tool for High-Throughput Analysis of Biological Systems

“…A stable attachment of probe molecules is usually achieved by forming covalent bonds to the surface [11,12]. Reactive groups for bond formation can be attached at the end of ( Fig.…”