Some general patterns emerge from the various techniques and reports on adenylation activity. First, many of the early methods measured the endpoint of a reaction and were not conducive to continuous measurements for kinetic analysis of A domains, instead requiring multiple separate reactions for each time point. We have delineated which of the methods below can be used in a continuous manner to reduce the time-consuming setup. Second, the addition of an acceptor molecule (either hydroxylamine or a downstream carrier protein) to the adenylation reaction, even when only the first half-reaction is being measured, often improves the reaction kinetics and encourages rection completion. Because of this, some assays found in primary literature may vary from the general procedures listed below. Our goal is to report first and foremost on the detection method and juxtapose it to others, leaving readers to determine which option best applies to their system.