The LEADING LIGHT® Wnt cell line medium pack (ENZ-60003) is made of a cell freezing medium, a cell growth medium concentrate, and a cell assay medium concentrate. These media contain additives such as antibiotics to maintain selection, stability, and integrity of the cells. I would strongly advise against using any other media to grow the cells and conduct the assay. Although these cells have been stably transfected, experimental conditions could be seriously affected without selection with the appropriate antibiotic. We also would like to add that the use of Cell Assay Medium is critical to guarantee good assay performance on the day of the experiment with activators and inhibitors of the canonical Wnt pathway.