Methods and kits for detecting kinase activity A method for measuring protein kinase activity comprising: (a) providing a first solution comprising ATP and a protein kinase to be tested, and a second solution comprising ATP in the absence of said kinase to be tested; (b) adding a substrate capable of being phosphorylated by the protein kinase to be tested to the first and second solutions of step (a); (c) measuring the concentration of ATP and/or ADP, or the rate of change thereof with respect to time, in each of the reaction mixtures formed in step (b) using a bioluminescence reaction; and (d) using the information about the concentration of ATP and/or ADP to determine the activity of the protein kinase to be tested.