Hello,

I am performing molecular beacon-based protein activity assays and the molecular beacon possesses a FAM and Dabcyl as a quencher. Mn2+ is a cofactor of one of my proteins and the samples which I added Mn2+ presented no fluorescence, lower values compared to the Master mix with Mg2+. Is Mn2+ a possible quencher? In previous experiments with a molecular beacon with TAMRA as a fluorophore I did not have this problem. Does anyone know if FAM is stable in a pH range from 8.5 to 5.5, and in high ionic strength solutions? I want to test different NaCl concentrations: from 0 to 500mM.

It would be nice to have more info before ordering new molecular beacons…

Thanks!