Biosearch Technologies, Inc. (BTI) announced that it has been awarded U.S. Patent No. 7,334,701 describing the CAL Fluor® series of fluorescent dyes. These xanthene dyes were developed at Biosearch Technologies by Mark Reddington and Matt Lyttle for the purpose of modifying synthetic DNA to enhance its detectability.
In pursuit of this purpose, each molecule contains a spacer arm attachment that eliminates problems commonly associated with xanthene dyes such as multiple isomers and low synthesis yields.
To facilitate the preparation of dye oligo conjugates, several CAL Fluor dyes synthons are available, including phosphoramidites and CPGs. These synthons are compatible with all commercial DNA synthesizers allowing rapid and efficient synthesis of 3’, 5’, and internally modified DNA. These advanced dyes help automate DNA synthesis by eliminating the manual methods of succinimidyl ester-coupling.
The CAL Fluor dyes are perfect partners to Biosearch Technologies’ Black Hole Quencher® (BHQ®) dyes described under U.S. Patent No. 7,109,312. The BHQ cloaks the fluorescence of the CAL Fluor dye until a specific target analyte is encountered. Target recognition releases the fluorescent signal which is easily recorded using devices such as real-time PCR thermal cyclers.
Both mechanisms of FRET and static quenching contribute to excellent signal to noise ratios from probes labeled with CAL Fluor and BHQ dyes.
Each of the five CAL Fluor dyes emits signal at different wavelengths across the spectrum, from 540 – 640 nm. By combining multiple CAL Fluor dyes in the same reaction, different analytes can be assayed simultaneously but detected independently. On most popular thermal cyclers, CAL Fluor dyes are proven to perform as many as 5-plex qPCR assays. This multiplexing capability was recently demonstrated at the 2007 International qPCR Symposium in Freising, Germany with an assay that identifies and quantifies environmental pathogens.
In DNA applications, CAL Fluor dyes are integral components to many genetic assays including diagnostic tests for veterinary and human health, biodefense, and the monitoring of agricultural and food processes. Flexible licensing programs are available ranging from basic research use only to fully validated in vitro diagnostics.
DNA probes labeled with the CAL Fluor technology are available from Biosearch Technologies and from BTI-licensed suppliers located in major markets around the globe.