Carrier-red blood cells (C-RBC) can be administered by intraperitoneal injection (IP) in mice, and C-RBC survive in circulation as well as cells administered by intravenous injection (IV). There was no difference in the 24 hr post-injection organ distribution of normal RBC and C-RBC, an indication of the normalcy of C-RBC. Approximately 25% of the C-RBC remain in circulation 14 days post-injection indicating a 20-day half-life for C-RBC in mice. This alternate injection method for RBC also allows for extravascular targeting of RBC to peritoneal macrophages.