Malvern zetasizer nano s instrument

Size determination of aggregates and the colloidal stability of the sample dispersions were determined by dynamic light scattering measurements, where the hydrodynamic diameter of particles, and zeta potential values were collected. The number-weighted size distribution indicated one main peak in each case, the polydispersity index (PDI) was calculated as sd²/mean size². For the particle size analysis Malvern Zetasizer Nano S instrument and for the zeta potential determination Malvern Zetasizer Nano Z instrument were used (Malvern Panalytical Ltd., Great Malvern, Worcestershire, UK). The measurements were carried out in autocorrelation mode, and the following parameters were kept constant: scattering angle 173°, attenuator 11 and its factor 0.0146, measurement position 4.65 mm. The concentrations of sample dispersions were between 0.3125 and 5 µM. The dispersion medium was PBS. Each samples was examined after 6 min incubation period at 37 °C.

First, 10 µM Aβ₄₀ oligomers (monomer equivalents) were incubated for 2 h in the absence and presence of increasing concentrations of DesAbs (20 mM Tris, 100 mM NaCl, pH 7.4) at 20 °C. SLS measurements were performed using the Malvern Zetasizer Nano S instrument (Malvern Panalytical, Malvern, UK) with fixed parameters (attenuator 9, cell position 4.65 mm), equipped with a Peltier temperature controller (25 °C). A low volume (70 µL) disposable cuvette was used (BrandTech Scientific, Essex, CT, USA). Samples containing trodusquemine were incubated (1 h, 20 °C) at an oligomer concentration of 5 µM (20 mM Tris, 100 mM NaCl, pH 7.4) in the absence or presence of the small molecule at concentrations ranging from 5 µM to 50 µM.