Monitor quality attributes in-process, not just process parameters.

Real-time process monitoring and control software for ultraDAWN™

OBSERVER acquires real-time multi-angle light scattering data from ultraDAWN, then calculates and reports molar mass, radius, and/or particle concentration, thirty times each minute.

Where most PAT instruments monitor process conditions such as temperature, concentration and feedstock, OBSERVER’s RT-MALS provides analytics and process control based on actual product quality attributes. When the RT-MALS results deviate from specifications or reach the process end point, OBSERVER can send a trigger to control the process, directly or indirectly via OPC.

For an overview of how OBSERVER analyzes MALS data to determine molar mass, size and particle concentration, please see Understanding Multi-Angle Light Scattering.

OBSERVER is a compact application that provides essential real-time functionality:

Workflows: Select from the Online Macromolecule workflow, designed for polymers and proteins, or the Online Nanoparticle workflow, designed for viruses, liposomes, and similar nanoparticles. Auxiliary workflows include Performance Qualification and (automated) Cleaning.

Pump control: In online mode, an HPLC pump is controlled by OBSERVER to pull a constant flow from the main process stream or container, with optional dilution.

Triggers: Depending on the workflow, OBSERVER can be set up to provide an analog or digital trigger based on the value of the molar mass, size, particle concentration or light scattering intensity. This trigger is used to control the process.

Self-checks: OBSERVER will pause its monitoring and provide indication of conditions that prevent good measurements, e.g. an air bubble in the flow cell or saturated detectors arising from exceedingly high particle concentrations.

OPC-AU connectivity: for full-scale production and GMP compliance, OBSERVER can be a an OPC-AU client for control by SIPAT or DeltaV.

OBSERVER, real-time MALS

Operation of OBSERVER is based on customizable workflows:

  • Online Macromolecules – for controlling processing of polysaccharides, proteins, etc.
  • Online Nanoparticles – for controlling processing of viruses, LNPs, liposomes, etc.
  • Performance Qualification
  • Automated cleaning


Online Macromolecules

OBSERVER’s Online Macromolecules workflow:

  1. Acquires MALS data 30 times per minute
  2. Calculates, records and plots:
    • Mw – weight-average molar mass
    • Rg – z-average rms radius
    • R0 – LS intensity (excess Rayleigh ratio)
  3. Activates trigger if values meet pre-defined criteria

OBSERVER, real-time MALS

Online Nanoparticles

OBSERVER’s Online Nanoparticles workflow:

  1. Acquires MALS data 30 times per minute
  2. Calculates, records and plots:
    • R – z-average radius
    • PC – particle concentration
    • R0 – LS intensity (excess Rayleigh ratio)
  3. Activates trigger if values meet pre-defined criteria
  4. Reports particle concentration and total number of particles in collected fraction

OBSERVER, real-time MALS

Wyatt Software System Requirements

Please see Host Computer Requirements for details of the computer hardware and operating system required by OBSERVER.

Factory integration - via bi-directional OPC-UA. May be operated in local mode when not connected to an OPC-UA client.

21CFR11 compliance - via compliant OPC-UA client software. When connected to an OPC-UA client, parameters cannot be set locally; all parameters are set and validated, and the run initiated, remotely via the OPC-UA client.

Maximum run duration - 12 hours