Dr Chattopadhyay has made outstanding contribution to the study of the organization and dynamics of ion channels in membranes. His incisive studies have clarified many features of gramicidis channel function. He has developed widely used fluorescence techniques for probing the structure of biological membranes using wavelength selective excitation. He has extended biophysical characterization of membrane proteins to the difficult problem of bovine hippocampal serotonin receptor. His work has contributed many key insights into the understanding of biological membranes.