We want to perform an enzymatic activity assay using the fluorogenic substrate 4-MU-beta-glucopyranoside (end-point readout, measurement of fluorescence at 440nm). The cells we are using for the assay express TagBFP, which shows a spectral overlap with 4-MU (the cleaved substrate). Is there a way to inactivate or quench the TagBFP? I read that TagBFP unfortunately shows an extremely high pH stability. Thank you!