Comparison of whole blood and soft tissue counts following injection of uncoated and Fog-1 G1Δnab-coated RBCs. Subject 6 was injected with 15 MBq uncoated ^99mTc-RBCs followed, after 20 minutes, by 49 MBq Fog-1 G1Δnab-coated ^99mTc-RBCs and was monitored by whole blood counting and gamma camera imaging of the soft tissue of the thighs. Blood sample counts were normalized by the ratio of mean image counts to the mean blood counts for the 0- to 20-minute period and overlaid on the time-activity curve of the soft tissue region.