(AB) Bioluminescence of mice post i.v. injection of 2×104 luciferase-labeled HEK 293T cells (three luciferase-luciferin pairs for comparison: teLuc-DTZ, Antares2-DTZ, and Akaluc-AkaLumine). BALB/c mice (n=3) were imaged 1, 5, and 24 h post injection. Luciferin substrates at indicated doses were delivered via (A) i.v. and (B) i.p., respectively. (C) Bioluminescence of extracted organs of mice in the Antares2-DTZ and Akaluc-AkaLumine groups from panel B. H: heart, Lg: lung, Lv: liver, P: spleen, S: stomach, In: intestine, K: kidney, T: testis, and B: bladder.