What is a gene expression microarray profile and how is it used to make clinical decisions in cancer therapy?

This is a DNA chip (DNA strands- representing genes -attached to a substate surface such as ceramic) that is used in profiling gene expression. Using cDNA probe from a subject,  and which are tagged with a flourescent marker,  they are used to identify which genes of the patient, that are normally off have been turned on, and conversley, which genes have been turned off which are normally on. This is therefore important in cancer diagnosis.

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