This guide covers aspects of designing microarray experiments and analysing the data generated, including information on some of the tools that are available from non--commercial sources. Concepts and principles underpinning gene expression analysis are emphasised and wherever possible, the mathematics has been simplified. The guide is intended for use by graduates and researchers in bioinformatics and the life sciences and is also suitable for statisticians who are interested in the approaches currently used to study gene expression.* Microarrays are an automated way of carrying out thousands of experiments at once, and allows scientists to obtain huge amounts of information very quickly* Short, concise text on this difficult topic area* Clear illustrations throughout* Written by well--known teachers in the subject* Provides insight into how to analyse the data produced from microarrays