Publisher Summary This chapter presents an overview of the strategies and methods of Drosophila genetics that are most useful to the cell biologist. The chapter illustrates ways to obtain a collection of mutagenized chromosomes and outlines a way to clone a gene associated with an interesting mutant phenotype. The chapter discusses the ways to screen for desired phenotypes. Examining large numbers of flies for a rare mutation is extremely labor intensive. Thus, the efficiency of a mutagen is a major consideration, although this needs to be weighed in terms of the desirability of the sorts of mutations produced. The chapter discusses the various types of mutagenesis that are routinely employed, along with considerations that may govern the choice of a particular method. In many cases, investigators induce mutations on wild-type chromosomes so as to avoid any decrease in viability resulting from the use of a multiply marked chromosome. However, inducing the mutation on a marked chromosome can be subsequently advantageous in identifying homozygotes.