Quasar® 670 is an indocarbocyanine which fluoresces in the red region of the visible spectrum. This compound is a direct replacement for Cy5™. Quasar 670 amidite is used for the 5' labeling of fluorogenic probes used in 5' nuclease assays Molecular Beacons™ and other detection assays. This amidite does not contain a DMT protecting group and can only be added to the 5' terminus of the oligo or internally on a free hydroxyl. BHQ®-2 will quench the Quasar 670 moiety.