CruzFluor™ sm 7 (CFLsm7) family has the spectral properties similar to those of Cy7, IRDye 800 and Alexa Fluor® 750. 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 CFLsm7-labeled peptides and nucleotides exhibit stronger fluorescence and higher photostability than the ones labeled with Cy7, IRDye 800 and Alexa Fluor® 750. In pairing with our CruzQuench™ 7 (CQ7), a variety of FRET peptides and nucleotides can be developed for detecting proteases and molecular beacons with enhanced sensitivity and stability.