Fig. 1From: Characterization of DNA topoisomerase I in three SN-38 resistant human colon cancer cell lines reveals a new pair of resistance-associated mutationsFISH analysis of TOP1 (red) and CEN-20 (green) aberrations in parental and SN-38-resistant cells. Shown are representative cell metaphase FISH images of parental (HCT116-Wt, HT29-Wt and LoVo-Wt) and SN-38 resistant (HCT116-SN38, HT29-SN38 and LoVo-SN38) cell lines. HCT116-SN38A and –B designate the two subpopulations observed in the HCT116-SN38 cell line. See text and Table 1 for details. Note: Due to the existence of two chromatids in each metaphase chromosome, the observed number of gene signals is double that of what is observed in an interphase nucleusBack to article page