CruzFluor™ sm 5 (CFLsm5) family has the spectral properties essentially identical to those of Cy5. Compared to Cy5 probes CFLsm5 family has much stronger fluorescence and higher photostability. Additionally their fluorescence is pH-independent from pH 3 to 11. These characteristics make this new dye family a superior alternative to Cy5. CFLsm5-labeled peptides and nucleotides exhibit much stronger fluorescence and higher photostability than the ones labeled with Cy5. In pairing with our CruzQuench™ 5 (CQ5), a variety of FRET peptides and nucleotides can be developed for detecting proteases and molecular beacons with enhanced sensitivity and stability.