The genome of an organism can be viewed as the source code for the programs that control the chemical processes of the cell.The genome also contains the hereditary endowment that an organism passes to its offspring. Large-scale computation is a crucial tool, both for sequencing a genome and for interpreting it once it has been sequenced. Applications of combinatorial optimization, statistical analysis, pattern recognition and computational learning are abundant. The speaker will describe some of these applications, with physical mapping, a key step in genome sequencing, as the principal example. He will then describe the important new technology of DNA arrays and describe some of the associated computational problems.