<p>(<b>a1-a2</b>) Treatment of MCF-7 cells with fluorescent-tagged ERaptD4 produced a shift of 84% relative to unstained MCF-7 cells. Figure in inset provides the fluorescent microscopy image of the FAM-ERaptD4 treated cells. (<b>b1-b2</b>) A shift of 20% is observed in MDA-MB-231 cell upon treatment with fluorescent-labelled ERaptD4. (<b>c1-c2</b>) The treatment of MCF-7 cells with a random sequence (FAM-labelled non-enriched aptamer library) produced no shift, indicating the lack of binding by the random sequence. FAM-labelling of the non-enriched aptamer library is carried out using PCR amplification with FAM-forward primer and biotin-reverse primer. Strand separation is performed on streptavidin magnetic beads. (<b>d-e</b>) Aptacytochemistry of ERα-positive MCF-7 and ERα-deficient MDA-MB-231 cells. Size-bar on images a-c is 100 pixels (imaging at 63X). Size-bar on images d-e is 200 pixels (imaging at 20X).</p
