Microarrays and its applications
Microarrays are large arrays of DNA sequences attached via automatic equipment to a solid substrate .
- These displays are also known as microchips, biochips, gene chips and DNA chips. It’s better to name them microarrays, to keep them from being confused with computer chips.
- DNA microarrays are thin, strong supporters that are immobilised at fixed positions in sequences of thousands of different genes.
- Typically glass microscope slides are the supports themselves, but silicon chips or nylon membranes may also be used. .The DNA is printed, spotted or actually directly synthesised onto the support mechanically at fixed locations or addresses. DNA, cDNA or oligonucleotides may be the spots themselves.
- The approach is based on probing hybridization. A fluorescent tag or flourescein on the individual beach sequences on the microarray is labelled and on the support in fixed positions.
- In microarray trials, an unknown sample is hybridised into a set of immobilised DNA molecules of known sequence, which can be analysed and compared with the given standards in order to achieve a certain hybridisation pattern.
- The labelled solution DNA strand is commonly referred to as the target, while the microarray DNA is immobilised, a terminology opposite Southern blot.
In contrast to other nuclear acid methods, microarrays have the following advantages:
- High throughput: On a relatively limited surface area, thousands of array elements can be stored, allowing gene expression to be controlled at the genomic level. It is also possible to track multiple components of a microbial population simultaneously in a single experiment.
- High sensitivity: small quantities of the target and the probe are limited to a small region, ensuring high concentrations and a very fast response.
- Differential display: it is possible to mark different target samples with different fluorescent tags and then hybridise them into the same microarray, enabling two or more biological samples to be analysed simultaneously.
- Low background interference: very low non-specific binding to the solid surface results in fast removal of organic and fluorescent compounds during manufacturing that bind to microarrays.
- Automation: Similar to other nucleic acid technologies, microarray technology is resistant to automation, ultimately making it cost-effective.
Applications of Microarray Technology
- Microarray technology is still new, but has been used in a variety of fields that are significant in general microbiology as well as in industrial microbiology and biotechnology, including disease detection, drug discovery and toxicological testing.
- In studying gene expression, microarrays are particularly useful. By leveraging the ability of a given mRNA molecule to bind directly to or hybridise to the DNA template from which it originated, a microarray operates.
- It is possible to establish, in a single experiment, the expression levels of hundreds or thousands of genes inside a cell by calculating the amount of mRNA bound to each site on the array by using an array containing several DNA samples.
- The amount of mRNA attached to the spots on the microarray is precisely determined with the assistance of a computer, producing a gene expression patterns in the cell.
- The bioactive potential of a particular microbial metabolite as a beneficial material in the form of a drug or its deleterious effect can thus be determined.
- If microarray studies detect a diseased condition, tests can be designed to be able to identify compounds from microbial metabolites or other origins that may boost or reverse the diseased condition.