Figure 3.
Identification of SP cells in Fine Needle Aspirates (FNAs) taken from palpable clinical breast tumours. Staining FNA samples with 2.5μg/ml Hoechst 33342 dye identified an SP of 0.4% (A). Adding 50μm verapamil prior to the Hoechst incubation (HS VP) inhibited Hoechst efflux from the SP (B). An example of an SP-negative FNA sample (C).