The LED fluorescence macroscope can image 5 fluorescent fluorophores in normal muscle and T-cell acute lymphoblastic leukemia (T-ALL). Whole animal imaging of wild-type (Negative), mylz2-Amcyan, mylz2-GFP, creatine kinase-zsYellow, mylz2-mCherry transgenic zebrafish (A-D). Amcyan was imaged by the use of a blacklight and 480/30 filter (A,J,N), GFP (blacklight, 520/30 filter; B,K,O), zsYellow (blue light, 575/52 filter; C), dsRED express (green light, 610/40 filter; L,P), and mCherry (green light, 610/40 filter; D). Transgenic zebrafish imaged using an epi-fluorescence stereomicroscope at the lowest magnification (7.0×; E-H). The LED fluorescence macroscope is also capable of imaging engraftment of T-cell acute lymphoblastic leukemia in recipient animals. Whole-animal imaging of recipient fish transplanted with 1.5 × 10⁴ Amcyan-, GFP-, or dsRED express–labeled leukemia cells at 30 days after transplantation (I-L). Animals from panels I through L were mixed to demonstrate that fluorescent-labeled animals can be easily delineated (M-P). Transplant recipients imaged by the use of an epi-fluorescence stereomicroscope at low magnification (7.0×, Q-T). Scale bars are 2 cm in panels A through D and I through L, and 5-mm in panels E through H and Q through T.