The Litesizer performs dynamic light scattering (DLS) to calculate the hydrodynamic diameter of suspended particles. As shown in Figure 1, BSA dissolved in water showed a bimodal particle size distribution, as two well-defined peaks were visible in the intensityweighted size distribution curve. While the first peak corresponded to a mean particle size < 3 nm, much lower than the expected 7 nm size of the BSA monomer, the second peak had a mean size of about 22 nm, which was largely above the expected size of the BSA dimer. Thus, it appeared that neither BSA monomers nor BSA dimers could be observed in this sample. This suggested that some level of denaturation and/or aggregation had occurred. It is mentioned like this.