Adeno-Associated Virus serotype 1 (AAV1) exhibits high homology with other AAV serotypes. AAV1 efficiently transduces muscle tissue, as determined by a region of the capsid protein VP1 (amino acids 350 to 430) which functions as a major determinant of tissue tropism.These AAV particles constitutively express the firefly (Photinus pyralis) luciferase and mCherry genes connected via a T2A linker, under the control of a CMV promoter. The T2A self-cleaving peptide (derived from Thosea asigna virus 2A) leads to the efficient cleavage of the transcript, and expression of luciferase and mCherry as two separate proteins.