Fig. 6. Aptamer-based platforms for label-free cell isolation. A mixed cell population is incubated with aptamer-labeled magnetic spheres, which bind specifically to the target cell. After magnetic separation to remove non-target cells (gray), labeled target cells remain. A reversal agent, or oligonucleotide complementary to a sequence within the aptamer, is added to release aptamer binding, resulting in a label-free target cell population. (A) Separation of EGFR+ cells (green) spiked in blood. Adapted from Gray et al.157 (B) Separation of CD8+ cells (purple) from PMBCs. Adapted from Kacherovsky et al.33 (C) Serial elution of CD4+ (red) and CD8+ (purple) cells from PBMCs. Adapted Cheng et al.94.
