Wyatt Technology

Composition-Gradient, Multi-Angle Static Light Scattering (CG-MALS) is a powerful technique for characterizing a wide range of biomolecular interactions.


Label-free and immobilization-free, CG-MALS is a rigorous yet versatile first-principles technique that measures interactions directly by monitoring the changes in solution molar mass that arise from the formation or dissociation of complexes. Apply CG-MALS to characterize:

  • Self- and hetero-association
  • Binding affinity from pM to mM
  • Absolute molecular stoichiometry (not just mole ratios)
  • Multi-valent or cooperative interactions; simultaneous self- and hetero-association
  • Kinetics of binding, aggregation or dissociation over time scales of seconds to hours

Self- and Hetero-Association

CG-MALS characterizes self- and hetero-association.

Binding Kinetics
CG-MALS works by mixing different compositions of samples and diluents, then measuring the weight-average molar mass of the solution at each composition step. Binding kinetics are often apparent.

CG-MALS also characterizes non-specific interactions between proteins at high concentrations and between proteins and excipients, which impact colloidal stability of formulated biotherapeutics. This email address is being protected from spambots. You need JavaScript enabled to view it. to learn how CG-MALS can address your specific biomolecular interaction analyses, such as:

  • Drug-target binding for monoclonal antibodies or bispecific fusion proteins
  • Monovalent or multi-valent receptors
  • Self-association under a variety of buffer conditions
  • Multi-protein assemblies in structural biology
  • Colloidal stability at protein concentrations of 100 mg/mL and beyond

Protein Assemblies

CG-MALS excels at analyzing multi-protein assemblies.

Instrumentation for CG-MALS

  • Composition-Gradient System

    Calypso, CG-MALS, dawn-heleos-II, binding affinity determination, light scattering, protein measurement, 
              coefficient analysis

    Calypso® - Composition-gradient preparative system + software for carrying out and analyzing CG-MALS interaction analyses. Requires MALS detector.

  • MALS Detectors

    dawn-heleos-II, CG-MALS, binding affinity determination, light scattering, protein, stoichiometry measurement, 
              coefficient analysis

    DAWN® - The most sensitive MALS detector available, anywhere. 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

    miniDAWN® - Second only to the DAWN in sensitivity. Incorporates detectors at 3 angles to determine molar masses from 200 Da to 10 MDa and radii from 10 – 50 nm. Ambient only.

  • Dynamic Light Scattering Detector

    WyattQels, CG-MALS, dawn-heleos-II, binding affinity determination, light scattering, protein measurement, coefficient analysis

    WyattQELS™ - A dynamic light scattering (DLS) module which integrates into a DAWN or miniDAWN MALS detector to provide simultaneous DLS measurements in the same MALS scattering volume.

  • Refractive Index Detector

    Optilab-T-rEX, CG-MALS, dawn-heleos-II, binding affinity determination, light scattering, protein measurement, coefficient analysis

    Optilab® - A unique on-line differential refractometer for measuring concentration of any macromolecule, regardless of chromophores. The high-concentration Optilab accommodates protein concentration up to 180 mg/mL.

  • Accessories


    COMET - An ultrasonic transducer that cleans MALS flow cells automatically by agitating the fluid and loosening particles from the glass surfaces. This module may be integrated into a DAWN or miniDAWN.

    microCUVETTE - Allows static and/or dynamic light scattering measurements to be made in a quartz cuvette in a DAWN, in order to reduce sample consumption to the bare minimum - requiring only 10 µL per composition step. Samples are prepared manually rather than by means of the Calypso II, while the CALYPSO software is still used to acquire and analyze data.

    Orbit - In a CG-MALS system, the Orbit is used to automatically choose wash solvents in the post-experiment cleaning cycle.

    RI Calibration Kit - Pre-made RI calibration standards are available to speed up RI calibration. Can be used to calibrate any Optilab or third-party differential RI instrument.

    Solaris - Prevents growth of bacteria, fungi or algae in solvents with high efficiency and protects your system from down-time due to contamination.


Ultimate Guide

Thirteen key questions to ask when buying a Multi-Angle Light Scattering (MALS) or Dynamic Light Scattering (DLS) instrument.

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Solutions Catalog

Our Solutions Catalog combines Wyatt's product lines, applications and services into a single comprehensive booklet.

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Wyatt Technology is the recognized leader in light scattering instrumentation and software for determining the absolute molar mass, size, charge and interactions of macromolecules and nanoparticles in solution.

Wyatt's line of multi-angle static light scattering products couple to size exclusion chromatography (SEC-MALS), field-flow fractionation (FFF-MALS), and stop-flow composition-gradient systems (CG-MALS). Our dynamic light scattering (DLS) products operate in traditional cuvette as well as on-line and automated, high-throughput modes. We also offer unique instruments for electrophoretic light scattering (MP-PALS), differential refractometry, and differential viscosity.

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