Dynapro ms x dls instrument

Dynamic light scattering (DLS) was measured with a DynaPro MS-X DLS instrument (Wyatt, Santa Barbara, CA, USA). Dynamics v6 software (Wyatt Technology Corporation, Santa Barbara, CA, USA) was used for data collection and processing. Sets of DLS data were measured at 15 μM and 25 °C unless stated specifically, with an average of 50 acquisitions and an acquisition time of 10 s.
Static scattering intensities were measured with a DynaPro MS-X DLS instrument (Wyatt, Santa Barbara, CA) or a Malvern μV instrument (Malvern Panalytical, Malvern, UK) at 25 °C in 50 mM sodium phosphate buffer (pH 7.4) at varying protein concentrations in the range of 0.2–4.5 g L⁻¹. The intensities were analyzed using a Debye plot as represented by Equation (1)
$$K·c/R_{90}=1/M_w+2A_{2}c$$
which is valid for particles significantly smaller than the wavelength of the incident radiation, where K is the optical constant of the instrument, c is the particle mass concentration, R₉₀ is the Rayleigh ratio of scattered to incident light intensity, M_w is the weight-averaged molar mass, A₂ is the 2nd virial coefficient that is representative of interparticle interaction strength and M_w can be determined according to the intercept of the plot.

The apparent hydrodynamic radii of the proteins were measured using dynamic light scattering (DLS) in a DynaPro MS-X DLS instrument (Wyatt, Santa Barbara, CA, USA). Dynamics v6 software (Wyatt Technology Corporation, Santa Barbara, CA, USA) was used in data collection and processing. Sets of DLS data were measured at 25 °C with an average number of 50 acquisitions and an acquisition time of 10 s. Measurements were carried out in 50 mM sodium phosphate buffer pH 7.4 and 50 mM glycine/HCl buffer pH 2.5.
Static scattering intensities were measured in a Malvern μV instrument (Malvern Panalytical, Malvern, UK) at 25 °C, in 50 mM sodium phosphate buffer pH 7.4, at different concentrations of protein in a range of 0.2 to 3.5 mg mL⁻¹. The intensities were analyzed using the Debye plot as represented by Equation (1),

valid for particles significantly smaller than the wavelength of the incident radiation, where the K is an optical constant of the instrument, c is the particle mass concentration, R₉₀ is the Rayleigh ratio of scattered to incident light intensity, M_w is the weight-averaged molar mass, and A₂ is the 2nd virial coefficient that is representative of inter-particle interaction strength. M_w can be determined from the intercept of the plot.