• protein aggregation;
  • particle sizing;
  • light scattering;
  • proteins;
  • analytical biochemistry;
  • subvisible particles;
  • flow cytometry;
  • FACS;
  • fractionation of aggregates


Protein aggregation, which takes place both in vivo and in vitro, is an important degradative pathway for all proteins. Protein aggregates have distinct physicochemical and biological properties that are important to study and characterize from the perspective of both fundamental and applied sciences. The size of protein aggregates varies across a huge range, spanning several orders of magnitude. Currently, protein aggregates larger than hundreds of nanometers in diameter are impossible to physically fractionate. Here, we present a new method to fractionate microscopic proteinaceous particles using preparative fluorescence-activated cell sorting technology. © 2013 Wiley Periodicals, Inc. and the American Pharmacists Association J Pharm Sci 102:2128–2135, 2013