Wyatt Technology

The Best in Basic Multi-Angle Light Scattering for Absolute Macromolecular Analysis

The miniDAWN® TREOS® II determines absolute molar mass and size to characterize proteins, peptides, small polymers and nanoparticles in solution. Coupled to size exclusion chromatography (SEC or GPC), it eliminates the uncertainty and hassle of column calibration, for true confidence in macromolecular characterization.

The TREOS II not only offers superb sensitivity—it further enhances productivity thanks to some unique capabilities: field serviceability, upgradeability to UHPLC and One-Click Mw™.

Included with each miniDAWN is a copy of ASTRA, the most versatile software package available for analysis of online multi-angle and dynamic light scattering. ASTRA and the TREOS II incorporate advanced ease-of-use features that help guarantee excellent measurements with a single click.

Learn about the technical advances introduced in the TREOS II in the free white paper, The Next Generation Compact MALS Detector.

  • Molar mass, absolutely

    The miniDAWN TREOS II is most often used in conjunction with Size Exclusion Chromatography (SEC-MALS) or Field-Flow Fractionation (FFF-MALS) to determine distributions of molecular weight, size and composition. No need to make assumptions about molecular conformation or ideal column interactions.

    • Proteins, small peptides and oligonucleotides
    • Synthetic and natural polymers
    • Nanoparticles, virus-like particles and vesicles

    Measurement Range:

    • MW from 200 Da to 10 MDa
    • rg from 10 to 50 nm, up to 150 nm with shape-specific models
    • sensitivity down to 25 ng of 100 kDa polystyrene in THF, injected on a standard GPC column

    TREOS II performance is exceeded only by the DAWN HELEOS II which covers a wider range of size and molecular weight, with even better sensitivity and additional optional modules.

    protein molar mass characterization 
        with miniDAWN TREOS II

    The miniDAWN TREOS II determines molecular weight independently of column calibration. Here MALS shows that the earliest-eluting molecule does not have the highest molar mass.

    Ultrasonic Cleaning Included

    COMET - An ultrasonic transducer that cleans MALS flow cells automatically by agitating the fluid and loosening particles from the glass surfaces. Integrates inside the miniDAWN.

    Modularity = Productivity

    The TREOS II incorporates a fully modular design. Each module can be tested independently by the software to verify that it is functioning correctly. This imparts two key capabilities:

    • Field serviceability - Malfunctioning modules can be replaced and validated on-site by service engineers
    • Upgradeability to UHPLC - If the users decides to transition to UHPLC, the standard HPLC optical module can be replaced with a UHPLC-compatible, micro-flowcell optical module*.

    *Micro-flow cell module is sold separately

    Optional modules for the TREOS II include the WyattQELS DLS Module for measuring hydrodynamic radii from 0.5 to 50 nm, and the automated COMET ultrasonic flow cell cleaner.

    Not just SEC-MALS...

    The TREOS II may be used in batch (off-line) mode or in conjunction with a Calypso II II CG-MALS system for characterization of average solution properties as well as macromolecular interaction properties including protein-protein binding affinity and complex stoichiometry.

    TREOS II upgrade to UHPLC

    The miniDAWN TREOS II may be upgraded to UHPLC by simply swapping the standard optical module for a micro flowcell optical module.

    Simplicity personified

    With the TREOS II and ASTRA, SEC-MALS became a whole lot easier. Sample-specific methods are set up in three short steps with ASTRA's Method Wizard, and new capabilities for automatic data processing mean that it takes just one click from your sample to a full report of the molecular weight and size results.

    The TREOS II's System Ready monitor will even let you know when the system is fully equilibrated with low baseline noise, ready to run.

  • Dynamic Light Scattering

    WyattQELS - A dynamic light scattering (DLS) detection module which integrates inside the miniDAWN to provide simultaneous DLS measurements in the same scattering volume. The optical collection fiber is held in a dedicated 135° fiber mount.

    DynaPro NanoStar - Primarily used for batch DLS, the NanoStar does double duty as an online DLS detector by installing its optical collection fiber into the miniDAWN.

    Upgrade to UHPLC

    Micro-flow Cell Module* - A TREOS II can be upgraded to a µDAWN at the customer site by exchanging the optical bench, which includes the laser and flow cell (Micro-flow Cell Module). The light scattering detector is then ready for UHPLC use.

    *Module sold separately.

  • Basic On-line Configuration

    The miniDAWN may be positioned downstream of all types of standard GPC, HPLC or FPLC systems for analysis of molar mass and size distributions (see SEC-MALS page), and derivatives such as conformational analysis. For those systems equipped with a UV, RI, fluorescence or other type of concentration detector, the miniDAWN accepts 2 analog inputs so a 3rd-party concentration signal may be used in MALS calculations of molar mass. The miniDAWN is generally set up downstream of a UV detector and upstream of a RI detector.

    In most cases it is beneficial to connect an Optilab T-rEX as well as a UV detector. This permits universal concentration detection regardless of fluorophores or chromaphores. The combination of UV and RI signals is utilized in ASTRA's Conjugation Analysis algorithm to characterize binary complexes such as glycoproteins, PEGylated proteins, membrane proteins enveloped in surfactant, or block co-polymers.

    Advanced On-line Configurations

    The miniDAWN may also be connected to an Eclipse Field-Flow Fractionation system for characterization of macromolecules and nanoparticles from 1 nm to > 100 nm via FFF-MALS.

    Both SEC-MALS and FFF-MALS will benefit from an additional WyattQELS module for measuring nanoparticle size via dynamic light scattering. The WyattQELS utilizes the same laser and flow cell volume as MALS detection. Its collection fiber, placed at 135° to the laser beam, does not displace any of the three detectors in the miniDAWN.

    For analysis of natural and synthetic polymers, the ViscoStar III may also be added as well. Differential viscometry is an orthogonal means of determining molar mass and conformation.

  • MALS detectors may be operated in batch (unfractionated) mode when the analysis is targeted at:

      Macromolecular interactions
      • In order to characterize macromolecular or nanoparticle complexes which are disrupted by column shear or dilution
      • In order to measure binding affinity or reaction kinetics of macromolecules such as protein-ligand interactions


      Average solution properties
      • If the sample is not amenable to separation by SEC or FFF, to measure weight-average molar mass, and size as z-average radius
      • In order to validate SEC-MALS measurements:
      • to determine if large aggregates or other species are filtered out on the column
      • to determine if reversible aggregates dissociate subsequent to dilution on the column or FFF separation channel


    Calypso II - Automated sample preparation and delivery system for carrying out and analyzing composition-gradient MALS in a miniDAWN. Analyses include biomolecular interactions analyses high-concentration protein-protein interactions, Zimm plots and dn/dc as well as time-resolved MALS. Utilizes the CALYPSO software for interaction analysis.

    Microbatch Kit - Used to inject samples into the flow cell of a MALS detector, and in determining dn/dc with an RI detector.

  • Orbit - The Orbit helps conserve mobile phase by programmatically directing the solvent to either a waste bottle or back to the solvent reservoir. In a CG-MALS system, the Orbit is used to automatically choose wash solvents in the post-experiment cleaning cycle.

    SEC Columns - Wyatt offers silica-based columns specifically designed and tested for optimal SEC-MALS measurements of proteins and peptides.

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

    WISH - The Wyatt Injection System High-Pressure (WISH) triggers ASTRA data collection and is ideal for use in SEC-MALS without an autoinjector. Also used with an Optilab dRI detector for the determination of dn/dc values.

    Inline filters - critical to ensuring particle-free mobile phase and optimal light scattering measurements in SEC-MALS and FFF-MALS. Wyatt offers inline filters for aqueous and organic mobile phases, designed to be placed between the HPLC pump and sample injector. Post-column filters are not recommended.

  • ASTRA - Our comprehensive software solution for MALS and DLS analysis in chromatography, AF4 or batch mode, included with each detector. ASTRA is available in a 21 CFR(11) compliant version and offers additional options such as particle analysis and a research database.

    ASTRA's HPLC Control service allows for full digital synchronization between your HPLC system.

    ASTRA's Method Wizard lets you set up a default method optimized for your sample type in three easy steps:

    1. Select experiment type
    2. Input parameters
    3. Hit Run

    Once the method is ready, you are just a click away from MALS analysis with One-Click Mw™. ASTRA will:

    1. Synchronize data collection with your HPLC
    2. Autoset parameters to determine MW and Rg
    3. Generate custom reports and graphs
    4. Prepare for the next run


    CALYPSO - Software for automated composition-gradient MALS experiments: control of the Calypso II, data acquisition and analysis for biomolecular interactions and reaction kinetics as well as weight-average molar mass, z-average molecular size, and virial coefficients.

    HPLC Manager
  • Measurements  
       Molar Mass Range 200 Da to 10 MDa1
       Molecular Size Range (rg) 10 nm to 50 nm 1, up to 150 nm with shape-specific models
       Molecular Size Range (Rh, with    WyattQELS DLS module or
       DynaPro NanoStar)
    In flow mode, 0.5 nm – 50 nm1,2; batch mode, 0.5 nm – 1 µm1

    25 ng of 100 kDa polystyrene in THF3
    500 ng of BSA in PBS4

       Mobile Phase Compatibility All-solvent compatible (aqueous and organic). Wetted materials are 316 stainless steel, fused silica, and Kalrez.
       MALS Detectors High-gain, high dynamic range, static light scattering detectors at 3 angles
       Auxiliary Detectors Laser monitor for stabilization feedback; forward transmission monitor to correct signals for absorbing samples and to assess data quality.
       A/D Resolution

    Detector dynamic range > 16,000,000:1

    DLS Detector (optional) WyattQELS dynamic light scattering module installs directly inside the miniDAWN chassis.

    Alternatively, the optical fiber pickup of the DynaPro NanoStar cuvette-based DLS instrument may be installed in the miniDAWN.
    Laser Properties  
       Laser Wavelength 658 nm (nominal). Each instrument is individually characterized.
       Laser Power Control Programmable 10% - 100%
    Flow Cells Fused Silica, optimal for solvent refractive index < 1.50
       Analog Inputs

    2 differential analog inputs with 24 bit resolution; Input range -10 V to +10 V

       Analog Outputs

    1 analog output from user selectable measurements channels -10 V to +10 V

       Other Inputs/Outputs Alarm In, Alarm retransmit, Auto-Inject in, Autoinject contact closure, Recycle In, Recycle valve power
       Computer Interface Ethernet
       Processed Data Transmission Rate 36.6 Hz to 0.2 Hz
       Front Panel Display 162.5 mm, 16-bit, high resolution touch screen
    Dimensions 60 cm (L) x 36 cm (W) x 17 cm (H)

    1Typical. Actual range depends on dn/dc, sample concentration, sample conformation and chromatography conditions.

    2Upper limit assumes a flow rate of 0.5 mL/min.

    3Under HPLC-SEC conditions with 7.8x300 mm GPC columns.

    4Under HPLC-SEC conditions with Wyatt 7.8x300 mm SEC protein columns.

    Host PC requirements may be found in Computer Requirements.

    Specifications subject to change without notice.


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

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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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