Red blood cells from Tg⁺ mice have normal survival rates. (A) Background FITC signal from unstained peripheral blood cells collected from a representative Tg⁻ mouse on day 0. (B) FITC signal from in vivo biotin-conjugated peripheral blood cells of the same mouse stained with Alexa-488 strepavidin on day 0. (C) At day 21, 2 populations (older, biotin-conjugated peripheral blood cells and newer, unstained peripheral blood cells) of peripheral blood cells were identified in the same mouse. (D) The survival of peripheral blood cells from Tg⁺ mice (n = 3, open circles, average shown in gray circle, solid line) did not differ from that of Tg⁻ mice (n = 4, closed squares, average shown in gray square, dotted line).