Figure 4.

Multiplexed QD staining and spatial mapping of tumor antigens on single breast cancer cells. (a) Breast tumor BT-474 cell, and (b) breast tumor BT-20 cell; both were stained with cytokeratin-QD (green), Her-2-QD (yellow), epithelial specific antigen-QD (red), and the nuclear dye DAPI (blue). Control data: (c) BT-474 cancer cells treated with QDs conjugated to nonspecific bovine serum albumin, and (d) peripheral blood mononuclear cells (PBMC) treated with the same QD-antibody conjugates used in panels (a) and (b). (e) Fluorescence image of BT-474 cells labeled with FITC-conjugated antibody against cytokeratin, and (f) photobleached image after 20 seconds.