2.3. System characterization
2.3.1. Particle size measurement
The particle size distribution was measured using a laser diffraction
particle size analyzer (Mastersizer 2000, Malvern Instruments, Ltd.,
Worcestershire, U.K.). Samples were diluted by adding small aliquots
into a measurement chamber containing 0.01 M phosphate buffer
(adjusted to the same pH as the samples) until the instrument gave
an optimum obscuration rate between 10 and 20%. The particle size
distribution was calculated from the light scattering pattern using
Mie theory. A refractive index of 1.33 was used for the aqueous phase,
and 1.472 for the protein phase.