Protein higher order structure (HOS) includes the secondary, tertiary and quaternary structures of a protein, which comprise the three dimensional structures that are necessary for structure and function. Proteins in solution are dynamic molecules which can sample an ensemble of structures in solution, and have molecular properties which results in differing propensities to self associate and form a range of species from oligomers to visible particles. Changes in the HOS of proteins can contribute to the quality attributes, and potentially safety, efficacy, and pharmacokinetic properties of protein therapeutica. Regulatory agencies require assessment of HOS to assess how protein structure is affected by manufacturing, storage and delivery; and analytical biosimilarity is an important part of evaluating potential changes in clinical safety and efficacy. There are many biophysical characterization methods and tools used in monitoring the attributes of protein therapeutics such as conformation and higher order structure. However, since most biophysical analyses provide ensemble average structural information of the molecules, it is essential to evaluate if the observed changes are significant and are tracking changes in CQAs, and cannot be attributed to assay or process variability. Use of the appropriate biophysical method, method development and qualification to characterize the quality attributes at different stages of the product lifecycle are therefore a matter of interest and debate for a wide range of audiences. This Symposium will focus on various biophysical methods for assessment of protein HOS, as well as the applications of the appropriate tools during the different stages of protein therapeutic development and biosimilarity assessments, the theory and practice of biophysics, technical data from academia and industry as well as method qualification, validation and setting specifications.