Agents to induce readthrough of premature termination codons (PTCs) are useful research tools and potential therapeutics. Reporters used to detect PTC readthrough are gene-specific and thus are not suited to for general assessment of readthrough activity or in cases where PTC-inactivated genes are unknown. Here we describe a GFP-based reporter construct pMHG-W57* which is capable of detecting dose-dependent drug-induced PTC readthrough both by fluorescence microscopy and flow cytometry. pMHG-W57* may be used as a general indicator of PTC readthrough in living cells and obviates the need for gene-specific recoding sequences in reporter constructs.