"Peptides corresponding to the substrate sequences L/VP4.1 and non-hydrolysable linker (NHL) were synthesized between a 5-carboxyfluorescein (5-FAM) fluorophore/CPC Quencher (CPQ2) quencher pair (CPC Scientific). Additional lysines were added for increased solubility giving final peptide sequences of CPQ2-IVYELQGP-K(5FAM)-KK-NH2 and CPQ2-GGSGGS-K(5FAM)-KK-NH2 for L/VP4.1 and NHL, respectively. The identity and sequence of the L/VP4.1 and NHL peptides were confirmed by CPC Scientific via LC-MS and determined to be 96.7% and 95.1% pure, respectively."