Tide Fluor 6WS (TF6WS) 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 6WS (TQ6WS), a variety of FRET peptides and nucleotides can be developed for detecting proteases and molecular beacons with enhanced sensitivity and stability.  This TF6WS product is reactive to alkynes, and useful for click chemistry.