Ubiquitin Fluorophore Assay
The ubiquitin molecule is bound to a quenched fluorophore (e.g. Rhodamine 110).
CHOP Assay
The ubiquitin molecule is bound to an inactive reporter enzyme.
Internally Quenched Fluorophore pair (IQF) Assay
The ubiquitin molecule is bound a fluorophore-conjugated ubiquitin molecule.