The WyattQELS® embedded dynamic light scattering (DLS) module integrates into any Wyatt multi-angle light scattering (MALS) detector—the DAWN®, miniDAWN® or microDAWN®—in order to measure particle sizes online, in conjunction with standard size exclusion chromatography or the Eclipse® asymmetric-flow field-flow fractionation (AF4) system. This capability is utilized in the ASTRA® chromatography software to provide accurate macromolecular and nanoparticle size distributions.


  • Integrates directly inside the MALS detector, using the MALS laser and flow cell, for simultaneous MALS and DLS measurements
  • Does not introduce additional band broadening or interdetector delay
  • Range of hydrodynamic radius Rh with flow: DAWN – 0.5 nm to 200 nm; miniDAWN – 0.5 nm to 50 nm; microDAWN – 0.5 nm to 30 nm
  • Range of hydrodynamic radius Rh without flow: 0.5 nm to 1000 nm in all MALS detectors.


  • Protein and polymer size and conformation
  • Accurate, high-resolution nanoparticle size and shape distributions