Fig. 5. Deuteration improves fluorescent properties beyond tetramethylrhodamine dyes. (A) Deuterium installation on one or two methyl groups leads to d3 or d6 variants of Coumarin 461. (B) Excitation and emission spectra of Coumarin(-d3/6). (C) Deuterium installation on both methyl groups leads the d6 variant of NBD. (D) Excitation and emission spectra of NBD(-d6). (E) Deuterium installation on the methyl groups leads to d12 variant of methylene blue(-d12). (F) Excitation and emission spectra of methylene blue(-d12).