One of the most challenging tasks facing the modern biological research laboratory is to make sense of the enormous amount of data being generated by various genome projects currently underway, and especially the human genome project. Understanding the ways in which genes are differentially expressed in various tissues and cell types, throughout ontogenetic development and in pathological processes, will go a long way towards understanding the function of all these 'new' genes and their protein products. Differential Display explains in detail how to perform the technique of RT-PCR Differential Display in various kinds of experimental biological systems. It also examines this technique in the context of other methods of studying differential gene expression such as subtractive hybridisation and the use of high-density gene microarrays combined with hybridisation techniques and automatic image analysis.