Abstract
In the last years, planarians have emerged as a unique model animal for studying regeneration and stem cells biology. Although their remarkable regenerative abilities are known for a long time, only recently the molecular tools to understand the biology of planarian stem cells and the fundamentals of their regenerative process have been established. This boost is due to the availability of a sequenced genome and the development of new technologies, such as interference RNA and next-generation sequencing, which facilitate studies of planarian regeneration at the molecular and genetic level. For these reasons, maintain a healthy and stable planarian population in the laboratory is essential to perform reproducible experiments. Here we detail the protocol used in our laboratory to maintain the planarian species Schmidtea mediterranea, the most widespread as a model.