The University of Massachusetts Amherst

Wyatt Technology/Agilent SEC-MALS


Conventional size exclusion chromatography relies on reference standards that do not accurately represent your molecules. SEC-MALS measures molar mass directly, independent of elution time, for confidence in reported values.

Not all macromolecules behave alike. Your samples may have a different conformation than molecular standards or exhibit unexpected column interactions. As an absolute technique for determining molar mass and rms radius rg in solution, SEC-MALS - the combination of Size Exclusion Chromatography with Multi-Angle Light Scattering analysis - overcomes the limitations of column calibration.

SEC- MALS-coupled with an analytical HPLC system can be used characterize:


  • Heterogeneous biopolymers and synthetic polymers
  • Oligomers and aggregates
  • Conjugates such as ADCs, PEGylated proteins, or block co-polymers

Multi-angle static light scattering (MALS) requires precise alignment of the beam direction, laser polarization and detector position in order to provide accurate measurements.

Users will need to provide their own columns and mobile phases.



SEC-MALS Instrumentation in the Biophysical Characterization Facility


DAWN HELEOS II - Incorporates detectors at 18 angles to determine molar masses from 200 Da to 1 GDa and radii from 10 – 500 nm.

--Heated/cooled option: -15°C to +150°C
--High-temperature option: to +210°C

  • MALS Detector

Optilab T-rEX - A unique on-line differential refractometer for measuring concentration of any macromolecule, regardless of chromophores.

  • Refractive Index Detector