Breeding of inbred strains is often towards specific phenotypes of interest such as behavioural traits like alcohol preference or physical traits like aging, or they can be selected for traits that make them easier to use in experiments like being easy to use in transgenic experiments. One of the key strengths of using inbred strains as a model is that strains are readily available for whatever study one is performing and that there are resources such as the Jackson Laboratory, and Flybase, where one can look up strains with specific phenotypes or genotypes from among inbred lines, recombinant lines, and coisogenic strains. The embryos of lines that are of little interest currently can be frozen and preserved until there is an interest in their unique genotypical or phenotypical traits.