Explain the basic principles of how an oligonucleotide microarray operates, showing h

[ManGer]

Explain the basic principles of how an oligonucleotide 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.

Thank you for any help.

[Max546]

To answer your question:
The probes correspond to short oligonucleotide sequences thought to be representative for a given gene. Each oligonucleotide is represented by two probes: one with the exact sequence and one with a mismatch nucleotide. Hybridization occurs at a critical temperature where a single nucleotide mismatch can prevent hybridization. White = strong hybridisation, black = no hybridisation. Based upon the hybridization ratio between PM and MM, it is determined whether a gene is ‘Absent’, ‘Marginal’ or ‘Present’.