The TCF/LEF Reporter kit is designed for monitoring the activity of Wnt / b-catenin signaling pathway in the cultured cells. The kit contains transfection-ready TCF/LEF luciferase reporter vector, which is a Wnt pathway- responsive reporter. This reporter contains a firefly luciferase gene under the control of multimerized TCF/LEF responsive element located upstream of a minimal promoter. The TCF/LEF reporter is premixed with constitutively expressing Renilla luciferase vector that serves as internal control for transfection efficiency. The kit also includes a non-inducible firefly luciferase vector premixed with constitutively expressing Renilla luciferase vector as negative control. The non-inducible luciferase vector contains a firefly luciferase gene under the control of a minimal promoter, without any additional response elements. The negative control is critical for determining pathway specific effects and background luciferase activity.