Growing and expanding primary, differentiated adult cells in culture is difficult and laborious because many differentiated cells can only be maintained in vitro for a limited period of time. However, for controlled experiments, it may be necessary to maintain a consistent population of cells.Maintaining a population of adult stem cells (ASCs), allows one to exponentially propagate a population of cells in vitro, and induce differentiation when desired. This is possible with SACK cell strains and specified cell culture conditions.SACK ASC cell properties Long-term propagation in xanthine (Xn)-supplemented mediumSuppressed asymmetric cell kineticsExpress the epithelial stem cell biomarker LGR-5Xn-suppressed non-random sister chromatid segregationDifferentiated progeny cell properties Xn-free medium, confluent monolayer, serum reductionSebocyte differentiation as well as other undefined cell typesInduced expression of K5, K10, and filaggrin