10xUAS drives expression of a stop codon readthrough reporter that consists of the 5' UTR from Syn21, the pLUC coding sequence (without stop codon), UGAC (encodes a UGA stop codon), a flexible linker, the NanoLuc coding sequence and the p10 3'UTR. The ratio of pLUC/NanoLuc luminescence serves as an estimate of stop codon readthrough.