200x Ubi-Mix(TM)

The 200x Ubi-Mix(TM) is a mix of Europium cryptate-labeled Ubiquitin (donor), Cy5-labeled Ubiquitin (acceptor), and unlabeled Ubiquitin at a ratio optimized for TR-FRET based assays where long and/or branched polyubiquitin chains are formed. Under conditions where short ubiquitin chains or multi-monoubiquitylation on a substrate protein are expected, a different reagent might be required. Since both the TR-FRET donor and acceptor are incorporated into poly-ubiquitin chains, using 200x Ubi-Mix(TM) avoids time-consuming washing steps and allows for monitoring polyubiquitination real-time kinetics