The WRN Helicase Activity Assay is a fluorogenic assay designed for screening and profiling of WRN (Werner Syndrome ATP-dependent Helicase) antagonists/inhibitors by monitoring their effect on WRN-catalyzed DNA unwinding. WRN inhibitor NCGC is also included as a control.

Figure 1: Illustration of the assay principle.
The DNA probe is conjugated on one strａnd with the TAMRA (tetramethylrhodamine) fluorophore, and on the other strａnd with BHQ (Black Hole Quencher) which effectively quenches TAMRA fluorescence due to their proximity within the DNA double strand. WRN unwinding of the DNA probe separates the two strands, releasing TAMRA fluorescence. WRN activity, therefore, results in a proportional increase in fluorescence.