TCDD-inducible poly-ADP-ribose polymerase (TIPARP; also known as PARP7 and ARTD14) is a mono-ADP-ribosyltransferase that has emerged as an important regulator of innate immunity, stem cell pluripotency, and transcription factor regulation. Characterizing TIPARP\'s catalytic activity and identifying its target proteins are critical to understanding its cellular function. Here we describe methods that we use to characterize TIPARP catalytic activity and its mono-ADP-ribosylation of its target proteins.