Figure 1.

MicroPET imaging of a mouse using a [⁶⁴Cu]-labeled antibody fragment targeted against carcinoembryonic antigen (CEA) in a xenograft model. The mouse carried a C6 glioma xenograft on the left shoulder (negative control) and a LS174T xenograft expressing CEA on the right shoulder (arrows). The mouse was injected with 26 μCi ⁶⁴Cu-anti-CEA minibody and imaged at 5 h, with the highest retention in the LS174T tumor (arrow) and liver, and lower retention in the control tumor (arrowhead). The liver signal occurs due to metabolism of the antibody fragment at that site.