HTRF® from Cisbio international is the homogeneous binding assay technology of choice: just mix and read. SNAP-vitro HTRF® kits enable the direct labeling of SNAP-tag fusion proteins with donor and acceptor fluorophores for HTRF® binding assays. As SNAP-tag labeling is gentle and precise, the inactivation of the protein during labeling is avoided. The protocol uses a single reagent and works even in crude lysates.

HTRF® is a time resolved fluorescence resonance energy transfer (TR-FRET) technique. In order to perform HTRF® binding assays, one binding partner is labeled with a long lifetime fluorophore (Eu3+ cryptate, or TBP) and the other binding partner with a suitable acceptor fluorophore. Long lifetime acceptor fluorescence is only seen where the two binding partners interact and so are close enough to each other for energy transfer from the excited Eu3+ cryptate to the acceptor.

HTRF®  is a registered trademark of CIS bio international