Steve Fodor and colleagues at Affymax built the first scanner in 1989, around the same time as they built their first microarray. A photograph on the Affymetrix Web site captures the device. It shows ...

The first step in using a microarray is to collect healthy and cancerous tissue samples from the patient. This way, doctors can look at what genes are turned on and off in the healthy cells ...

But how, exactly, does this process work? To better understand how microarray analysis is carried out, consider the example experiment described in the following sections.