Microrheology involves tracking the motion of dispersed tracer particles of known size by Dynamic Light Scattering (DLS) and determining the rheological properties of the sample using the Generalized Stokes-Einstein Relation. DLS Microrheology is a passive microrheology technique, whereby the colloidal probe particles only undergo thermal fluctuations in a system at thermodynamic equilibrium.

DLS Microrheology is applicable for the rheological characterization of low viscosity and weakly-structured complex fluids, such as dilute solutions of polymers and surfactants through to concentrated protein formulations. For these types of materials, Microrheology offers significant advantages:

  • Probes very high frequencies necessary for characterizing inherent short timescale, viscoelastic responses (whereas mechanical techniques are fundamentally limited by inertia).
  • Only requires microliter-scale volumes for rheological characterization of materials where sample volume is limited e.g. protein-based formulations.

Applications of DLS Microrheology include:

  • Rheological characterization of therapeutic proteins and biopolymer solutions.
  • Viscoelastic measurements of protein solutions to assess onset of protein-protein interactions and insoluble aggregate formation
  • Formulation development and screening.
  • High frequency rheology of dilute systems on process-relevant timescales.
  • Monitoring structure development in complex fluids with time or temperature, or structure breakdown on dilution.

Zetasizer Advance Range

Zetasizer Advance Range

Light Scattering for every application

More details
Measurement type
Molecular size
Molecular weight
Particle size
Zeta potential
Protein mobility
Dynamic Light Scattering
Electrophoretic Light Scattering
Static Light Scattering
Temperature range