The Macromolecular Interactions Facility (MIF) in the Department of Biochemistry and Molecular Biology at the University of Melbourne is a key platform technology resource for the biophysical characterisation of proteins and other macromolecules. It brings together a number of state-of-the-art instruments for the analysis of protein size, shape, secondary structure, interactions and complex formation. The equipment is open to academic and commercial users, and training can be provided. Instruments in the facility include analytical ultracentrifuges, a circular dichroism spectrometer, isothermal titration calorimeter and biolayer interferometer. The analytical capabilities of our instruments also extend beyond proteins themselves and have been successfully exploited for the study of drug binding, intracellular aggregation processes, nanoparticles and other systems.