In vivo distribution of β2GPI-Cy5.5. Top panel: Whole body scan of one representative mouse of 4 that received β2GPI-Cy5.5 (50 μg) into the tail vein by Time-Domain Optical Imaging. The distribution of the labeled protein was followed at various time intervals for one week. The signal was rapidly detected in the liver after injection where persisted for 48 hours and was progressively seen in the bladder. The distribution pattern was similar in all treated animals. Bottom panel: Ex vivo imaging of organs isolated from a representative mouse killed one week after injection of β2GPI-Cy5.5 and analyzed by eXplore Optix. Note the presence of the signal in the liver and the uterus. All animals showed a similar organ distribution.