What is a DNA Microarray analysis?

DNA microarray (also called DNA microchip or gene array) is one of the modern DNA testing methods. It is used to identify which genes are expressing (functioning) in the particular tissue or organ in the body. It also can be used for forensic purposes.

What is the scientific basis of the method?

DNA microarray analysis is based on the ability of DNA to create double helix between complementary strands. Glass or silicon chip with arranged in order (array) single strands of known DNA sequences works as a litmus paper for sequences of interest in the sample.

First, the DNA is extracted from the biological sample (it can be a blood or any other tissue sample). Then typically double-stranded DNA is heated, which causes separation of strands.  Single strands of DNA from the sample marked by a fluorescent probe, one color for each sequence of interest. Consequently, this mixture applied to the microarray chip. Single strands of sample DNA bond with the complementary single strands of DNA in the chip. The rest of DNA that didn't bond gets washed away. Then laser scanner electronically captures the data. The laser, activating fluorescent dyes in the sample, scans chip. Computer then analyses the colors to show which sequence is bonded. Thus, the present of the fluorescent color indicates the presence of a particular sequence in the sample.

DNA microarray method is an efficient and fast technique to monitor thousands of genes at the same time.

What are the applications of this method?

This method can be applied in both academic and industrial settings.

Often researchers use microarray method to analyse the gene product – mRNA. The presence of mRNA indicates that gene is functioning. This testing is important to find out which genes are activated in response to the certain environmental factors or diseases. Received information can be utilised for the quick diagnosis as well as the treatment planning.

Pharmaceutical companies use microarray information to figure out exactly what molecular targets interact with drugs or hormones. DNA microarray helps pharmaceutical companies to choose the most appropriate candidates for clinical trials. It can assist with the creation of personalized medicines in the near future. The same method can be used for the toxicity assessment.

Cancer treatment strategies are also benefiting greatly from microarray analysis.

Large parts of the genome can be identified using this method for the general biological research.