Figure 7.

Uncertainty in the detected source depth versus cell number for samples containing magnetically labeled MCF7/Her2-18 human breast cancer cells located 4.5 cm below the SQUID sensors. The data demonstrate a detection sensitivity, obtained using our current hardware and SHP-30 SAO5 nanoparticles, of 940,000 cells at a depth of 4.5 cm. Theoretically, further improvements in the hardware and nanoparticles will result in even higher sensitivity. Her2, human epidermal growth factor-like receptor 2; SQUID, Superconducting Quantum Interference Device.