Protein and Nanoparticle Characterisation Using Light Scattering Techniques

Abstract The technique of dynamic light scattering is well suited to the measurement of the size of colloidal dispersions. Traditionally, measurements of large particle sizes or particles that are highly scattering would require high dilution of the sample in order to avoid multiple scattering effects. Conversely, measurement of very small and/or poorly scattering particles or samples that are very dilute are difficult unless high‐powered lasers are used. These problems have been addressed in a light scattering instrument incorporating novel non‐invasive backscatter optics (NIBS). This novel optic arrangement maximises the detection of scattered light while maintaining signal quality. In addition to the increased size and concentration range for DLS applications, the increased sensitivity obtained from this optical arrangement also allows for the determination of absolute molecular weight using static light scattering measurements. Accurate molecular weight measurements can be achieved at a single scattering angle for molecules that do not show any angular dependence in their scattering intensity. This paper describes the advantages of using backscatter optics and illustrates the capabilities of the technology by reporting results of measurements from various applications.