a method for homogeneously assaying biopolymer bonding includes obtaining signals from a test sample before , during and / or after the application of stimulus to the test sample and correlating the signals . the signals , whose magnitude correlate with binding affinity , can be , for example , electrical conductance and / or fluorescent intensity . the stimulus can be , for example , electric voltage and / or laser radiation . preferably , different types of signals are measured and compared so as to enhance the reliability of the assay .