A substantial body of scientific evidence now reveals that the main mechanism that drives cancer development and growth involves progressive cancer stem cell (CSC) overpopulation. Studying this mechanism, that is, studying the stem cell (SC) origin of cancer, has been seriously hindered, however, because no biomarkers are currently available that map and quantify effects on SC division in real time. The problem is that markers for identifying CSCs mainly use immunostaining of fixed cells – either ones that have been cultured in vitro or ones that exist in fixed tissue sections. Such analyses only provide a “snap shot” of stem cell (SC) populations at a single point in time and are not amenable to measuring changes in CSC populations in cancers over time and in response to drugs. Thus, availability of technology to measure CSCs would provide advanced methodology to assess the efficacy of drugs that are being designed to target CSCs. The current goal is to develop fluorescence imaging technology that is low cost, accurate and practical that provides a means to measure the effect of drugs on CSCs.