FIGURE 2:

P-Glu₄ is preferentially taken up by human breast cancer MDA-MB-231 cells over P-Gal₄. Cells were treated with 10 µM glycosylated porphyrin for 24 h, rinsed, and fixed with a 4% paraformaldehyde solution. Fluorescence images were taken under identical conditions. R,G,B vector analysis of the unmodified images indicates the average relative fluorescence intensity, taken to be proportional to the extent of conjugate uptake by these cells, is 2.3:1 for P-Glu₄/P-Gal₄.