In 2009 we published a method for measuring mitochondrial ADP-ATP exchange rate mediated by the adenine nucleotide translocase (ANT): Biophys J. 2009 Mar 18;96(6):2490-504.
An improved calibration step of this method has been published in Methods Enzymol. 2014;542:333-48
This methodology is presented in details in http://antactivity.com