A trifusion reporter plasmid is described that comprises a plasmid operably coupled to a mammalian FGF1B promoter that is operably coupled to a bioluminescence gene fused to a fluorescence gene fused to a nuclear medical imaging gene. The new reporter allows in vivo or ex vivo detection of gene expression in three different ways, in addition to traditional in vitro detection methods. Transgenic animals containing this new trifusion reporter and uses of same are described.