Labeled DNA on Surfaces

Heinz-Bernhard Kraatz, Yitao Long, and Todd C. Sutherland 

Department of Chemistry, University of Saskatchewan, Saskatoon, Saskatchewan, Canada 

Macromolecules Containing Metal and Metal-Like Element, 

Volume S Biomedical Applications, edited by Alaa S. Abd-El-Aziz, Charles E. Carraher Jr., Charles U. Pittman Jr., John E. Sheats, and Martel Zeldin ISBN 0-471-66737-4 Cop37right 2004 John Wiley Sons, Inc. 

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The reagent also has been used in a unique tRNA-mediated method of labeling proteins with biotin for nonradioactive detection of cell-free translation products (Kurzchalia et al., 1988), in creating one- and two-step noncompetitive avidin-biotin immunoassays (Vilja, 1991), for immobilizing streptavidin onto solid surfaces using biotinylated carriers with subsequent use in a protein avidin-biotin capture system (Suter and Butler, 1986), and for the detection of DNA on nitrocellulose blots (Leary et al., 1983). 

A typical DNA array fabrication and application process involves three major steps. First, nucleic acids (the capture sequences or probes) are immobilized at discrete positions on surface activated substrates. Secondly, the resulting array is hybridized with a complex mixture of fluorescently labelled nucleic acids (the target), and thirdly subsequent to hybridization, the fluorescent markers are detected using a high-resolution scanning laser that quantifies the interaction. This chapter focuses on the first of these processes and provides the reader with an overview of substrates, surface activation methods and dehvery systems available for nucleic acid immobilization. 

Park, T Lee, S Seong, G. H Choo, J Lee, E. K Ji, W. H Hwang, S. Y Gweon, D. G and Lee, S. 2005. Highly sensitive signal detection of duplex dye-labelled DNA oligonucleotides in a PDMS microtluidic chip Confocal surface-enhanced Raman spectroscopic study. Lab on a Chip 5 437 2. 

The hybridization event can be detected both with label-free or enzymatic labelling procedures. The single-point attachment of DNA can be achieved by the immobilization of biotinylated DNA on Av-GEB platform. In this case, a one-step immobilization/hybridization procedure is achieved. The capability of surface regeneration of the biocomposite electrodes allows repeated analyses with the same electrode as... 

Micro- and nano-beads have become a major tool in analytical chemistry sciences. On one hand, micrometer size beads were developed with a very large range of properties such as magnetic and/or fluorescent beads, having different surface functional groups for coupling chemistry or physicochemical properties. On the other hand, few nanometer size particles were shown to be potential powerful labels for on chip detection of DNA strands. 

Malicka, J., et al. (2003) Fluorescence spectral properties of cyanine dye-labelled DNA oligomers on surfaces coated with silver particles. Anal Biochem 317 136-46. 

Fig. 13.6 Schematic representation of the SERRS detection assay, (a) When target DNA is not present the dye-labeled DNA probe is free to adsorb on the surface of the silver nanoparticles resulting in an intense SERRS signal (b) in the presence of target DNA the probe will hybridize to its complement and in this case, the dsDNA is not adsorbed onto the surface of the silver nanoparticles resulting in a reduction in the SERRS signal...

Fig. 23.9. Controlled deposition and hybridization of DNA on hydrophobic SU-8 surface patches (a—d) and defined displacement of DNA from such areas (e-f). (a) Schematic drawing of the individually labeled and cholesterol-modified DNA...

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