Dynamic light scattering studies of protein aqueous solutions provide valuable insight regarding protein physicochemical properties such as their molecular size, the existence of different populations (oligomeric protein aggregates) in solution and their size distribution, their hydrodynamic radius and diffusion behaviour. Furthermore, the determination of the molecular weight and radius of gyration, as well as the extraction of information about protein-solvent interactions and molecular shape is also possible by means of multi-angle static light scattering measurements. In addition, light scattering is one of the suitable techniques for studying protein interaction/complexation with other proteins, ligands or biomacromolecules, as well as their aggregation in response to external stimuli like temperature, pH, ionic strength, etc.
The Zetasizer Nano S is an instrument with high sensitivity and wide size range. It is a particle size analyzer for the enhanced detection of aggregates, measurement of small or dilute samples, or samples at high concentration, plus a molecular weight analyzer for molecular size and molecular weight measurement. Specifications of the instrument:
Molecular weight measurement down to ~1 kDa.
Automated temperature trend measurements.
Sample concentrations from 0.1ppm to 40%w/v.
Protein size measurement as dilute as 0.1mg/mL (Lysozyme).
Quality assessment software gives confidence in the data.
The Expert advice report gives help to improve sample preparation or the measurement procedure.
Alternative laser, 50mW at 532nm for samples incompatible with the standard 633nm laser fitted.
Minimum sample volume 12µL
Accuracy: Better than +/-2% on NIST traceable latex standards
Precision / Repeatability: Better than +/-2% on NIST traceable latex standards
Light source: He-Ne laser 633nm, Max 4mW
Operating temperature (°C): 10°C – 35°C