The Zetasizer APS transfers 20µL sample from each well to a precision quartz flow cell for measurement. The cell environment is optimized for precision temperature control and optical clarity to ensure the most accurate and precise results. This means that any industry standard disposable or reusable plate can be used without concern for transparency or scratches on the plate that would affect the result.

The Zetasizer APS enables you to:

  • Investigate your protein over a large number of environmental conditions with minimal user intervention.
  • Determine whether a protein is well-behaved in a buffer or whether aggregates are present.
  • Assess purity to screen for suitable crystallization buffers.
  • Measure aggregation temperature (melting point) to predict or compare stability.
  • Uses industry standard 96 or 384 well plates.
  • Measures size, size distribution, aggregation temperature.
  • Use multiple measurement protocols on a single plate.
  • Graphical plate scheduler to simplify set up.
  • Color coded results graphic to aid data interpretation.
  • Complete plate method stored for subsequent plates.
  • Plate sampling technology ensures highest result accuracy.
  • 2 - 90°C temperature range for measurement.
  • 4 - 40°C temperature range for protein storage.

The Zetasizer APS (Automated Plate Sampler) uses laser light scattering to determine a number of parameters that are associated with protein conformation and stability.
The system integrates a plate sampling system and measurement unit into a compact box to simplify use.

Dynamic Light Scattering (DLS) determines size by measuring the speed of Brownian movement of particles or molecules in a solvent or buffer. This diffusion speed is converted into a size, polydispersity and size distribution with knowledge of the temperature and buffer viscosity using the Stokes-Einstein relationship.

The size is used to determine oligomeric state, polydispersity provides the purity, and the size distribution is used to detect aggregates. Light scattering is very sensitive to the presence of aggregates, so is an ideal technique to determine the early stages of instability.

Particle size and molecular size

Measurement range:
Particle size and molecular size
Measurement principle:
Dynamic Light Scattering
Minimum sample volume:
Better than +/-2% on NIST traceable latex standards
Precision / Repeatability:
Better than +/-2% on NIST traceable latex standards
0.1mg/mL 15kDa protein (Lysozyme)

Aggregation temperature (melting point)

Measurement range:
2ºC - 90°C +/- 0.1.**
Measurement principle:
Dynamic light scattering
Minimum sample volume:
Temperature control range:
2ºC - 90ºC +/- 0.1.**
Compatible plate types:
96, 384 well (SBS standard) †
Light source:
Laser 830nm, max 60mW
Laser safety:
Class 1
Dimensions (W, D, H):
500mm x 410mm x 420mm (W, D, H)

Operating environment

Operating temperature (°C):
15°C – 30°C
35% - 80% non-condensing
Maximum range, sample dependent.
At 25°C

Zetasizer APS

PTC-1 Plate temperature control unit

Maintains the well plate at a constant temperature, primarily to preserve the protein before measurement.

Temperature range - 4°C to 40°C
Weight - 12.2kg
Dimensions - W:D:H, 200mm x 385mm x 310mm.
Power - 100V-240V AC, 50/60, 228W

SV-10 viscometer

Viscosity measurement with speed, simplicity and accuracy.


The SV-10 measures viscosity with the accuracy required for dynamic light scattering, for the conversion of diffusion speed to size, and electrophoretic mobility to zeta potential, in an extremely simple and rapid system.

More information