The Transcreener(R) HTS Assay platform overcomes the need for time-consuming one-off assay development for individual members within a group transfer enzyme family by utilizing a single set of assay reagents that detect an invariant product. The generic nature of the Transcreener(R) HTS Assay platform eliminates delays involved in assay development for new HTS targets and greatly simplifies compound and inhibitor profiling across multiple target families. The Transcreener(R) ADP2 fluorescent intensity (FI) assay extends the Transcreener(R) platform for ADP detection by utilizing a simple fluorescent intensity output which can be used on both fluorescence readers typically found in academic and therapeutic research labs as well as more complex multimode plate readers more commonly used in core facilities and HTS labs. The Transcreener(R) ADP2 FI Assay is a red competitive fluorescence intensity (FI) assay based on the detection of ADP and therefore is compatible with any enzyme class