A floxed PGK-neo and stop codon were place under the control of a CAG promoter and followed by a tricistronic insert composed of a histone tagged GFP, the avian sarcoma leucosis virus glycoprotein (EnvA) receptor (TVA), and the rabies glycoprotein B19G. The tricistronic insert is only expressed after cre excision of thge PGK-neo sequence and its stop codon. (J:197432)