The basic performance of a nanoparticle detection system for lymph node use
d with a high-Tc superconducting quantum interference device (SQUID) was in
vestigated. Ultra-small iron oxide particles of 360 pg could be detected wi
th spacing of 1 mm between the SQUID magnetometer and the particles, When t
he space was widened to 40 mm, the detectable weight of the particles was i
ncreased and was 1.6 mug.