NEPHELOstar Plus

Laser-based microplate nephelometer for light-scattering and turbidity measurements

The world’s first and only laser-based microplate nephelometer was developed to meet high-throughput demands for fast compound solubility screens. The NEPHELOstar® Plus detects insoluble particles in liquid samples by measuring forward scattered light and can be used for turbidity measurements, drug solubility screening, protein binding kinetics, microbial growth, and petroleum process control.

The first and only laser-based microplate nephelometer.



The NEPHELOstar Plus is a microplate nephelometer with a high-intensity laser diode. It can be up to thirty times more sensitive than traditional transmission optical density readers that measure the reduction in direct light passing through a sample well. Thanks to its speed, flexibility and performance, the NEPHELOstar Plus allows more applications to be adapted to microplate-based laser nephelometry than ever before.


  • Adjustable laser intensity and beam diameter for best performance
  • Measurement in up to 384-well microplate format
  • Linear, orbital and double-orbital shaking as well as uniform incubation up to 45 °C
  • High-precision injectors with simultaneous reagent injection and detection
  • Stacker and robot compatibility
  • Includes multi-user control and MARS data analysis software

Detection Modes

Nephelometry; Light Scattering

Measurement Modes

Endpoint and kinetic measurements

Microplate Formats

Up to 384-well plates

Microplate Carrier

Robot compatible

Light Sources

Self-monitoring laser diode
Wavelength 635±10 nm
Stability <0.2% deviation
Lifetime 20,000 hours
Output: 1 mW
Selectable beam width: 1.5 to 3.5 mm
Selectable Intensity 0-100%
Scattering angle: Detects up to 80° full cone angle


Side window photodiode detector

Wavelength Selection

Wavelength 635±10 nm


Depends on particle size and liquid properties
Silica detection (particle size 0.5 to 10 µm) 800 nM

Dynamic Range: 5 decades
Maximum count rate (2,000,000 Relative Nephelometry Units (RNUs) per second)

Read Times

Depend on assay conditions and liquid surface stability
16 s (96), 47 s (384) (shortest possible times)

Reagent Injection

Up to 2 built-in reagent injectors
Injection at measurement position (6 to 384-well)
Individual injection volumes for each well (3 to 500 µL)
Variable injection speed up to 420 µL / s
Up to four injection events per well
Reagent back flushing


Linear, orbital, and double-orbital with user-definable time and speed

Purge Gas Vent

System to inject an atmosphere or to pull a vacuum into the reader


+4°C above ambient up to 45 °C

The upper heating plate of the incubation chamber operates at 0.5 °C more than the lower plate. This prevents condensation build-up on the lid or sealer. 


Multi-user Reader Control and MARS Data Analysis Software included
FDA 21 CFR Part 11 compliant


Width: 44 cm, depth: 48 cm, height: 32 cm; weight: 25 kg

Optional Accessories


Magazines for up to 50 plates - continuous loading feature


Microplate Incubator and Shaker


Please contact your local representative for upgrades including options such as detection modes, reagent injectors, etc.

Optional Accessories