Tide Fluor™6 (TF6) family has the spectral properties similar to those of Cy5.5, IRDye 700 and Alexa Fluor 680. Their fluorescence is pH-independent from pH 3 to 11. These characteristics make this new dye family more robust to pH-sensitive assays. In some cases TF6-labeled peptides and nucleotides exhibit stronger fluorescence and higher photostability than the ones labeled with Cy5.5, IRDye 700 and Alexa Fluor 680. In pairing with our Tide Quencher™ 6 (TQ6), a variety of FRET peptides and nucleotides can be developed for detecting proteases and molecular beacons with enhanced sensitivity and stability.