Figure 2: Stable, long-term expression of CFP fluorescence in stably transfected rat hepatic ASC clones. Three cell clones expanded from CFP-transfected colonies, B1, B2, and B3 (as described in text), were propagated and serially analyzed for CFP expression. At the indicated number of population doublings, the percentage of fluorescence-expressing cells was determined by flow cytometry for each specified clone. The cells have been passaged for a maximum of 140 population doublings.