This chapter takes you through the maze of techniques that are used to analyse the genome, and you will be amazed at how they have made information on human health so accessible. They use the knowledge of DNA structure, as described in Chap. 1 , and the life cycle of the cell, as described in Chap. 3 . The methods used depend on the type of DNA variation that is either suspected or known about. It also relates to how these techniques are applied during screening and technology. Many of these techniques are complex and are constantly evolving. The downside of increased information is that the relevance of some of the discoveries is unknown. They also increase the risk of errors in interpretation, which could lead to legal challenges.