Excerpts

Using GFP2 as a template, an enhanced ratiometric pHluorin (pHluorin2) construct was developed to contain fully mammalianized codons, the F64L mutation and ten of the thirteen pHluorin-specific mutations. As a result, pHluorin2 displays markedly higher flores-cence when compared to pHluorin while maintaining the ratiometric pH-sensitivity.

Analogous to the development of the superecliptic pHluorin, inclusion of mammalianized codons and the F64L mutation in the ratiometric pHluorin backbone markedly enhances florescence while maintaining the desired pH-sensitivity, yielding a super-ratiometric variant called pHluorin2.