The Mac-In-Fac is a core biophysical laboratory of the University of North Carolina at Chapel Hill. It provides instrumentation and resources for biophysical characterization of interactions of biological macromolecules. The capabilities include measurement of affinity, stoichiometry, kinetics and thermodynamics of interactions among proteins, DNA and their cognate ligands. Resources exist for analyzing the biophysical characteristics of molecular weight, shape, and conformations of proteins and DNA; and for exploring bimolecular interactions in real-time. The facility is open to all researchers in the Triangle area on a first-come-first-serve basis. However, preference is given to UNC researchers.