DNA microarrays: Difference between revisions
No edit summary |
No edit summary |
||
| Line 1: | Line 1: | ||
DNA microarrays are used in functional genomics to determine the differences in gene expression levels between a sample and control cell<ref | DNA microarrays are used in functional genomics to determine the differences in gene expression levels between a sample and control cell<ref />. The sample cell can be from a different tissue, at a different stage of development, at a different stage of the cell cycle, or be under different conditions (for example, exposure to a toxin)<ref />. The DNA microarray consists of a flat surface to which oligonucleotides are bound<ref />. These oligonucleotides are complementary to specific cDNA sequences<ref />. The mRNA molecules within the sample and the control are converted into labelled cDNA molecules with the use of reverse transcriptase and fluorescently-labelled nucleotides<ref />. For example, the cDNA of the sample can have a red fluorescence label whereas the cDNA of the control can have a green fluorescence label<ref />. The DNA microarray is exposed to the cDNA mixture and unbound cDNA is washed away<ref />. The resultant DNA microarray consists of spots of colour that is imaged using a confocal fluorescence scanner<ref />. The colour of the spot is indicative of the differences in gene expression between the sample and control<ref />. Following the colour scheme above, a red spot indicates that the sample is overexpressing that particular gene compared to the control; a green spot indicates that the sample is underexpressing that particular gene compared to the control; and a yellow spot indicates that there is equal gene expression in the sample and control<ref />. However, the range of colours is not as discrete as suggested here but is more of a spectrum covering intermediate differences in gene expression<ref />. DNA microarrays are not so useful in determining gene function but can ascertain which genes may have the same regulatory mechanisms<ref />. | ||
<references /> Daniel L. Hartl, Elizabeth W.Jones (2009) '''Genetics Analysis of Genes and Genomes''' 7th Edition USA, Jones and Bartlett Publishers. | <references /> Daniel L. Hartl, Elizabeth W.Jones (2009) '''Genetics Analysis of Genes and Genomes''' 7th Edition USA, Jones and Bartlett Publishers. | ||
Revision as of 18:41, 13 November 2011
DNA microarrays are used in functional genomics to determine the differences in gene expression levels between a sample and control cellCite error: The opening <ref> tag is malformed or has a bad name. The sample cell can be from a different tissue, at a different stage of development, at a different stage of the cell cycle, or be under different conditions (for example, exposure to a toxin)Cite error: The opening <ref> tag is malformed or has a bad name. The DNA microarray consists of a flat surface to which oligonucleotides are boundCite error: The opening <ref> tag is malformed or has a bad name. These oligonucleotides are complementary to specific cDNA sequencesCite error: The opening <ref> tag is malformed or has a bad name. The mRNA molecules within the sample and the control are converted into labelled cDNA molecules with the use of reverse transcriptase and fluorescently-labelled nucleotidesCite error: The opening <ref> tag is malformed or has a bad name. For example, the cDNA of the sample can have a red fluorescence label whereas the cDNA of the control can have a green fluorescence labelCite error: The opening <ref> tag is malformed or has a bad name. The DNA microarray is exposed to the cDNA mixture and unbound cDNA is washed awayCite error: The opening <ref> tag is malformed or has a bad name. The resultant DNA microarray consists of spots of colour that is imaged using a confocal fluorescence scannerCite error: The opening <ref> tag is malformed or has a bad name. The colour of the spot is indicative of the differences in gene expression between the sample and controlCite error: The opening <ref> tag is malformed or has a bad name. Following the colour scheme above, a red spot indicates that the sample is overexpressing that particular gene compared to the control; a green spot indicates that the sample is underexpressing that particular gene compared to the control; and a yellow spot indicates that there is equal gene expression in the sample and controlCite error: The opening <ref> tag is malformed or has a bad name. However, the range of colours is not as discrete as suggested here but is more of a spectrum covering intermediate differences in gene expressionCite error: The opening <ref> tag is malformed or has a bad name. DNA microarrays are not so useful in determining gene function but can ascertain which genes may have the same regulatory mechanismsCite error: The opening <ref> tag is malformed or has a bad name.
Daniel L. Hartl, Elizabeth W.Jones (2009) Genetics Analysis of Genes and Genomes 7th Edition USA, Jones and Bartlett Publishers.