Our project enables cells to present different colors when they experience different numbers of cell-cycles.

     By lining up different recombinase UNITs (e.g. VIKA UNIT, VCRE UNIT)in COUNTER CIRCUIT activated by cell-cycle dependent promoters, and different florescence UNITs (e.g. mCHERRY UNIT, GFP UNIT) in the REPORTER CIRCUIT activated by constructive promoters, and an inducible tet-on STARTER CIRCUIT, our design enables cells to change one color once a cell-cycle. Therefore, by referring to the color chart, we can determine how many cell-cycles the cells have undergone.

     This can help confirm whether stem-cells used in stem cell therapy have successfully renewed and differentiated, and how many cell cycles they experienced. In fundamental stem-cell researches, our project can help distinguish actively self-renewing cells from quiescent cells which hardly proliferate. Apart from these, our project has many other potential applications in both fundamental and applied science.