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, up to 300 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-UA. OBSERVER can also transmit real-time measurements for use by process control software via analog voltage or digitally via OPC-UA.

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

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

Workflows: Select from Macromolecule workflows, designed for polymers and proteins; Nanoparticle workflows, designed for viruses, liposomes, and similar nanoparticles, or AAV workflows, designed for small viral vectors and similar gene or drug carriers. Each may be run in In-line mode (external source of flow, e.g. FPLC or TFF) or On-line mode (OBSERVER controls a quaternary pump to sample the process and flow solution through the ultraDAWN). Auxiliary workflows include Performance Qualification and (automated) Cleaning.

Pump control: In on-line mode, an auxiliary pump is controlled by OBSERVER to pull a constant flow from the main process stream or container, with optional dilution. In in-line mode, OBSERVER can exchange simple digital and analog signals with process software such as Cytiva’s UNICORN to synchronize flow and measurements.

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, genomic payload or light scattering intensity. This trigger is used to control the process.

Outputs: measurements may be transmitted in real time to external software as an analog voltage or digitally, via OPC-UA.

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-UA connectivity: for full-scale production and GMP compliance, OBSERVER can be controlled by an OPC-UA client such as SIPAT or DeltaV.

OBSERVER, real-time MALS

Operation of OBSERVER is based on customizable workflows:

  • Inline or Online Macromolecule –for monitoring and controlling processing of polysaccharides, proteins, etc.
  • Inline or Online Nanoparticle – for monitoring and controlling processing of viruses, LNPs, liposomes, etc.
  • Inline AAV – for monitoring processing of AAV, other small viral vectors or virus-like particles encapsidating nucleic acids, or small UV/Vis-active nanoparticles (up to ~ 50 nm in diameter) that encapsulate drug substances like peptide or small-molecule drugs.
  • Performance Qualification
  • Automated cleaning


In-line Macromolecule, Nanoparticle or AAV

OBSERVER’s in-line workflows:

  1. Synchronize with an FPLC or microfluidic system
  2. Report for the main process flow
    • Macromolecules: weight-average molar mass Mw and z-average rms radius Rg
    • Nanoparticles: z-average rms radius R and particle concentration PC
    • AAV: total, full and empty particle concentration; total, capsid and payload molar mass; full-total ratio; z-average rms radius Rg
  3. Report for the collected fraction
    • Macromolecules: Mw and total mass
    • Nanoparticles: PC and total number of particles
    • AAV: total, full and empty particle concentration; total, capsid and payload molar mass; full-total ratio; z-average rms radius Rg, and total number of capsids, number of full capsids and number of empty capsids.

OBSERVER, real-time MALS

On-line Macromolecule or On-line Nanoparticle

OBSERVER’s on-line workflows:

  1. Control an auxiliary pump to:
    • Draw a sample flow from the main process flow
    • Dilute the sample up to 10:1
    • Pass the sampled product to the ultraDAWN
  2. Report for the main process flow
    • Macromolecules: Mw and Rg
    • Nanoparticles: R and PC

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.

21 CFR Part 11 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 - 48 hours