The pGL4.77[hRlucP/Hygro] Vector encodes the luciferase reporter gene hRlucP (Renilla reniformis) and is designed for high expression and reduced anomalous transcription. This vector also contains a mammalian selectable marker for hygromycin resistance in which the number of transcription factor binding sites has been reduced and mammalian codon usage optimized. The pGL4 Vectors are engineered with fewer consensus regulatory sequences than the pGL3 Vectors and a synthetic reporter gene that has been codon optimized for mammalian expression. The pGL4.77[hRlucP/Hygro] Vector is a basic vector with no promoter. However, it contains a multiple cloning region that allows cloning of a promoter of choice. The hRlucP reporter gene contains hPEST, a protein destabilization sequence. The protein encoded by hRlucP responds more quickly and with greater magnitude to changes in transcriptional activity than the hRluc gene, its more stable counterpart.