DNA microarray

(redirected from DNA microarrays)
Also found in: Dictionary, Encyclopedia.
Related to DNA microarrays: CDNA microarray

DNA microarray

An orderly arrangement of DNA sequences on a small solid support, usually a membrane or glass slide, used to quickly survey the simultaneous expression of many genes. Also called DNA chip.
The American Heritage® Medical Dictionary Copyright © 2007, 2004 by Houghton Mifflin Company. Published by Houghton Mifflin Company. All rights reserved.
An array of DNA oligonucleotides synthesised in situ by photomasking on a semiconductor chip
Segen's Medical Dictionary. © 2012 Farlex, Inc. All rights reserved.

DNA mic·ro·ar·ray

A technique used to identify the entire gene expression of bacterial cells. Microscopic spots of DNA are placed on a solid support in an array, and unknown samples fluorescently labeled are hybridized to the DNA on the array. A scanner is used to identify hybrids.
Medical Dictionary for the Health Professions and Nursing © Farlex 2012

DNA microarray

A collection of tens of thousands of DNA single-strand molecular probes capable of detecting specific genes or measuring gene expression in a sample of tissue. A gene is expressed when it is transcribed into messenger RNA (mRNA) and forms a protein. Currently, DNA microarrays are mainly used as research tools but they have great potential as diagnostic devices and as a reliable means of predicting a patients' susceptibility to various diseases.
Collins Dictionary of Medicine © Robert M. Youngson 2004, 2005

DNA microarray

an orderly, low density arrangement of DNA samples, for example cDNA (see COPY DNA), immobilized as spots on a matrix. DNA microarrays can be fabricated by robotic spotting of single-stranded DNA PROBE molecules, on to the surface of a microscope slide, such that DNA of known identity is immobilized at precisely defined locations. A single slide may contain information for thousands of genes.

A typical DNA microarray/chip experiment involves matching known (probe) and unknown (target) nucleic acid samples on the basis of COMPLEMENTARY BASE PAIRING through HYBRIDIZATION, and automating the process of identifying the unknowns.

The target single-stranded nucleic acid sample, DNA or RNA, whose identity/ abundance is being determined, is labelled (see LABEL for example using a fluorescent dye, and incubated with the microarray/chip so that hybridization can occur between probe and target. Any unhybridized, free nucleic acid is washed away and HYBRID molecules detected by scanning and locating the positions of the fluorescent label. Abundance depends on the amount of fluorescence, whilst the position of fluorescence identifies the sample.

[Note: the definitions for the terms ‘probe’ and ‘target’ as used here differ from those used in classical hybridization. Here, the probe is immobilized and unlabelled, whilst the target is free and labelled.]

A problem with the use of microarrays is the potential for intra-strand BASE PAIRING in nucleic acid molecules, which could block probe-target interactions and hybrid formation. The use of PNA probes may circumvent this, since PNA:DNA hybrids can form under conditions that inhibit intra-strand base pairing in single-stranded DNA.

Microarrays/chips allow a large number of hybridization experiments to be carried out simultaneously in a single assay, so that thousands of GENES could be analysed in parallel. The technology can be used for a number of purposes including

  1. identification of genes;
  2. determination of the level of GENE/GENOME EXPRESSION in, for example, normal cells or tissues, diseased states, cell cycle analysis, and response to environmental stimuli;
  3. Detection of MUTATIONS and POLYMORPHISMS. For gene expression studies mRNA or cDNA is prepared and used to hybridize to specific probes. Hybrids identify the expressed genes.

Applications of the technology include drug discovery and development, human and agricultural diagnostics (see DIAGNOSIS), analysis of food and GMOs, SNP identification, and screening for TOXINS (see TOXICOGENOMICS).

DNA microarrays/chips are important tools in functional GENOMICS.

The terms ‘DNA microarray’ and ‘DNA chip’ are often used interchangeably although there is a technical difference. Other terminologies include biochip, gene chip, gene array

Collins Dictionary of Biology, 3rd ed. © W. G. Hale, V. A. Saunders, J. P. Margham 2005
References in periodicals archive ?
IAVchip DNA microarray [15,16] for early IAV detection and differentiation has been developed at the RIBSP (Research Institute for Biological Safety Problems) and now the ways of its use in practice are investigated.
DNA microarray data analysis was based on averaged background-corrected median values obtained from GenePix Pro 7 software.
DNA microarrays offer several advantages over in situ hybridization methods.
The dynamic, interactive, learning environment is a great instrument for the learning of genome expressions using DNA microarrays. It is aimed at various learning styles and multiple grade levels.
The book is divided into 15 chapters that can be broadly grouped under DNA microarrays, antibody microarrays and immunoassays, and methods to optimize sample quality as well as the resulting data.
Bochner's next invention came during the genomics era, when DNA microarrays allowed scientists to measure the expression of thousands of genes simultaneously.
"The great thing about DNA microarrays is that we can search for many genes at once in any particular sample," he says.
A team of Cancer Research UK scientists at Cambridge University used a technique called DNA microarrays to identify the new genes.
The developing complementary technologies of DNA microarrays and proteomics are allowing the response of bacterial pathogens to different environments to be probed at the whole genome level.
The European Patent Offices's Opposition Division has found in favour of Oxford Gene Technology (Oxford, England; 44-1865-722106) in the 6-year opposition to its European patent for DNA microarrays.
Editors Moretti and Rizzo (no affiliations listed) have collected research in the field on the use of oligonucleotides for detecting complementary DNA and RNA such as in DNA microarrays and the synthesis of artificial genes.