https://phys.org/news/2018-07-assay-reveals-biophysical-properties-proteins.html

In their quest to understand what exactly makes a protein a prion, Stowers Assistant Investigator Randal Halfmann, Ph.D., and his lab members focused on the very first event of prion formation, known as nucleation. They designed a powerful novel cell-based fluorescence assay called Distributed Amphifluoric FRET (DAmFRET) to determine some of the key biophysical properties of nucleation for proteins expressed in baker's yeast cells.

Halfmann and team members determined that the key property of prion-forming proteins that distinguishes them from other proteins is their ability to become super-saturated. "Unlike other proteins that began to aggregate as soon as they were sufficiently concentrated inside cells, prion forming proteins instead remained soluble, and only aggregated when very rare random fluctuations in a few molecules provided a template to do so," Halfmann said.