Explain the basic principles of how a cDNA microarray operates, showing how we can take advantage of some of the fundamental characteristics of the DNA molecule to determine gene expression in tissue samples taken from normal and ‘diseased’ cells?
Can anyone help please?
A DNA array typically a glass microscope slide that has been specially treated to remove all moisture then a specific silane monolayer is applied e.g. Amino Propyl Tri Ethoxy Silane. The DNA dots, really oligonucleotides, half of a DNA spiral are applied to the silane surface with a piece of equipment. If the silane has been applied correctly the dot sticks for years and the next step of the operation is to apply samples of different oligonucleotides to the treated slide. The applied dots are a range of DNA types and the other half of the DNA helix can only cling to the correct oligo. If the smple oligo,s have a fluorescent dye applied then only where they react will there be any fluorescence. By shining a light at the slide and seeing a fluorescence at say the third row and the fourth dot in you can state that that dot represents the sample DNA. Knowing the sequence of dots allows you to know instantly the disease that is represented in the sample.
Thank you very much for the helpful answer.