A Unique FACS Method to Isolate Stem Cells in Planarian

Fluorescence-activated cell sorting (FACS) is a useful method for stem cell biology, which enables us to isolate the living stem cells of interest from mixture of a variety of cells. In general, the target cells for FACS need to be labeled for various cell surface markers. However, in non-model organisms, we usually do not have specific labels for such cell surface markers. Here, we describe a method for isolating stem cells from non-model organisms, such as planarians, based on physiological and morphological properties of the stem cells. This method may also be applicable to other non-model animals.