Take advantage of time in your experiments: a guide to simple, informative kinetics assays

Understanding virtually any process in cellular and molecular biology depends on knowledge of the rates of the biochemical reactions, so it is regrettable that few cellular and molecular biologists take advantage of kinetics experiments in their work. Fortunately, the kinetics experiments that are most useful for understanding cellular systems are within reach for everyone whose research would benefit from this information. This essay describes simple methods to measure the valuable kinetic parameters that characterize the dynamics of life processes. These "transient-state" methods not only differ in concept from traditional approaches used to analyze enzyme reactions at steady state, but they are also applicable to learning about the dynamics of any biological process.