TFMU-ADPr is a selective reporter substrate of SARS-CoV-2 Macro1 (IC50=0.59 µM), with an excitation wavelength (lambdaEx) of 385 nm, and an emission wavelength (lambdaEm) of 502 nm (or 495 nm). TFMU-ADPr can also undergo enzymatic hydrolysis with Poly(ADP-ribose) Glycohydrolase (PARG) sourced from human, Tetrahymena thermophila and ADP-ribosylhydrolase 3 from human to release fluorophores, thereby directly reporting total poly (ADP-ribose) hydrolase activity. TFMU-ADPr binds to the ADPr-binding site of SARS-CoV-2 Macro1, and its TFMU moiety inserts into the narrow hydrophobic groove of this protein. TFMU-ADPr can thus be used to evaluate small-molecule inhibitors targeting PAR hydrolases under in vitro conditions, to investigate the regulatory mechanisms of ADP-ribosyl catabolic enzymes, or to detect PAR hydrolase activity in whole-cell lysate assays. TFMU-ADPr is also applicable to COVID-19-related research[1][2][3].