Relative quantification of breast cancer stem cells in MCF-7 and T47D cell lines and their mammospheres along with their characterization for stemness properties. (A) The percentage content of breast cancer stem cells (CD44+/CD24-/low) in MCF-7 and T47D cells, MCF-7/T47D-derived primary/1° and secondary/2° mammospheres, were determined by flow cytometry and represented graphically (right panel). The left panel depicts representative flow cytometry data. (B-D) Graphical representation of relative mean fluorescence intensities (MFIs) in arbitrary units (AU) of de-differentiation markers Oct-4, Sox-2, and Nanog; drug-resistance markers ABCG2 and MRP1; and stemness-related enzyme ALDH1 in MCF-7 and T47D cell lines, along with their respective 2° mammospheres as determined by flow cytometry (right panels). The left panels depict representative flow cytometric histogram overlay data. Data are presented as mean ± standard error of mean or representative of three independent experiments.