TFMU-ADPr triethylamine, a versatile substrate for evaluating poly(ADP-ribose) glycohydrolase (PARG) activity, enables direct measurement of total PAR hydrolase activity through the liberation of a fluorophore. With outstanding reactivity, generality, stability, and usability, it serves as an essential tool for the in vitro assessment of small-molecule inhibitors and exploration of the regulation of ADP-ribosyl catabolic enzymes [1].