The UAS-bla HEK 293T Master Cell Line consists of HEK 293T cells stably transfected with a UAS-bla fusion construct. This cell line can be used to build cell-based assays by transfecting with GAL4 fusion constructs. Activation of the GAL4 fusion results in binding to the UAS-bla and subsequent expression of beta lactamase. Expression of beta lactamase is monitored using a FRET-based assay.