This review concerns reversion of the argE3 (ochre) nonsense mutation to 
prototrophy in E. coli AB1157 strain as an informative system for mutation 
detection. Strain AB1157 bears the argE3 (ochre), hisG4 (ochre) and thr-1 
(amber) mutations, and the supE44 amber suppressor on its chromosome. The Arg(+) 
phenotype can be restored by (i) any base substitution at the argE3 site that 
changes the nonsense UAA codon to any sense nucleotide triplet or to UAG 
recognized by the supE44 amber suppressor, or (ii) suppressor mutations enabling 
the reading of the UAA nonsense codon. The argE3 → Arg(+) reversion-based system 
enables (i) determination of the spontaneous or induced mutation level; (ii) 
determination of base substitutions (suppressor analysis); (iii) examination of 
transcription-coupled repair (TCR) since targets for DNA damage are situated on 
the transcribed or coding strand of DNA; (iv) detection of mutations resulting 
from single stranded DNA damage. This review focuses on studies carried out 
since the early 1990s till now with the application of the AB1157-based mutation 
detection system. Recently, the system has been used to obtain new data on the 
processes of methyl methanesulfonate-induced mutagenesis and DNA repair in E. 
coli alkB⁻ mutants.