Question

With regard to DNA microarrays, answer the following questions: A. What is attached to the slide? Be specific about the number of spots, the lengths of DNA fragments, and the origin of the DNA fragments. B. What is hybridized to the microarray? C. How is hybridization detected?

Answer 1

A biochip or DNA chip or DNA microarray is a slide that contains the different fragments of DNA . The DNA microarray technique is used to study the expression level of various genes simultaneously. For this the researcher:

A. Attach the fragments of DNA about 500 to 5,000 bp that are produced by the controlled growth of the nucleotides by providing the narrow beam of light and synthesised by the PCR technique on to the slide in the form of dots or spots.

B. In dots, the reporter oligos or probes are attached which are used to hybridize the cDNA to the microarray. The cDNA is labeled with the fluorescent molecules called fluorophore.

C. After hybridization, the probe-target hybridization is detected by placing the washed array in the confocal fluorescence microscope which observes the pixel and helps calculate the fluorescence intensity.