Date recorded: October 07 2020

ZetaClass is a comprehensive webinar series on dynamic and electrophoretic light scattering where our experts walk you through the basic measuring principles, data interpretation and tests performed to gauge data quality. Whether you are a new or advanced user of light scattering solutions, we will answer all your questions.

Nanoparticles provide crucial functionality across a wide range of materials, applications and sectors. Dynamic light scattering analysis, together with zeta potential information, allows us to confidently measure the size distribution profiles of particles in the sub-micron range as well as asses the behaviour of these nanoparticles in suspensions.


DLS measures Brownian motion and relates this to the size of the particles. Brownian motion is the random movement of particles due to the bombardment by the solvent molecules that surround them. Normally DLS is concerned with measurement of particles suspended within a liquid. The velocity of the Brownian motion is defined by a property known as the translational diffusion coefficient (usually given the symbol, D).

The Hydrodynamic Diameter is a value that refers to how a particle diffuses within a fluid and this is the size of a particle that is calculated from the translational diffusion coefficient using the Stokes-Einstein’s equation. This in turn is dependent upon various factors such as Temperature, surface structure, ionic strength of the medium etc.

This week we shall discuss the Basic Measurement Principles used in Dynamic Light Scattering (sometimes referred to as Photon Correlation Spectroscopy or Quasi-Elastic Light Scattering) for measuring the size of particles typically in the sub-micron region.

The physical components and features of a dynamic light scattering (DLS) instrument along with the instrument’s technical specifications are obviously important considerations when purchasing a new system. The purchase of a light scattering system, however, sometimes requires multiple researchers or several labs to work together to find an instrument that suits the needs of everyone involved. It is in these cases where the answer to the “What type of samples will I be analyzing” question becomes complex because not only must you understand your own samples but you must then also understand the needs of others who will be sharing the instrument.

Every model of DLS instrument has its own strengths and weaknesses and there are usually trade-offs involved when considering a wide range of applications or sample types. The best model to choose would be the one which suits and is meant for satisfying that specific application area. This week we shall discuss the different models of the Zetasizer range offered by Malvern Panalytical and their advantages.

This session is led by Dr Anand Tadas, Malvern Panalytical's regional application specialist who has a wealth of knowledge in biologicals and DLS. Interested to improve your R and D / manufacturing process and gain more knowledge about the applications of particle size distribution using DLS? Scroll down to register your interest for our series of biopharma webinars.

Join our free ZetaClass series 

- ZetaClass 1: The best Dynamic Light Scattering (DLS) system for your particle characterization requirements. More info
- ZetaClass 2: Dynamic Light Scattering (DLS) data interpretation and troubleshooting. More info
- ZetaClass 3: Electrophoretic Light Scattering (ELS) for Zeta potential measurements. More info
- ZetaClass 4: Applications of Zetasizer Advance series across different sectors of the industry. More info