pAce is a positive polarity fluorescent voltage sensor (shows an increase in fluorescence during voltage depolarization events). It consists of a voltage-sensitive rhodopsin sequence fused via a linker to the fluorescent mNeonGreen protein (PMID:36378956). pAce was generated by mutagenesis of Ace2N-2AA-mNeon2, containing in addition the mutations R78K, S81D, D92N and W178F. For detailed kinetic and spectral properties and a comparison of pAce with other fluorescent voltage indicators, see PMID:36378956.