The Eclipse quencher from ELITechGroup solves most of the problems inherent in the synthesis of molecular beacon and FRET probes. The Eclipse molecule is highly stable and can be used safely in all common oligo deprotection schemes. The absorbance maximum for Eclipse Quencher is at 522 nm, compared to 479 nm for dabcyl. In addition, the structure of the Eclipse Quencher is substantially more electron deficient than that of dabcyl and this leads to better quenching over a wider range of dyes, especially those with emission maxima at longer wavelengths (red shifted) such as Redmond Red and Cyanine 5. In addition, with an absorption range from 390 nm to 625 nm, the Eclipse Quencher is capable of effective performance in a wide range of colored FRET probes.