SRY-box transcription factor 9 (SOX9) is a transcription factor that plays a key role in regulating genes involved in chondrogenesis, cartilage and skeletal development, and sexual differentiation. The SOX9 luciferase reporter vector is designed to study the transcriptional activity of SOX9. The vector contains a SOX9 DNA consensus binding site and TA minimal promoter upstream of a firefly luciferase reporter gene, which can specifically report SOX9 activity while maintaining a low basal level of transcription.