microOptilab Refractive Index Detector for UHPLC

The microOptilab® differential refractive index (dRI) detector is specifically designed for use with any UHPLC system. It works alone as a universal concentration detector, or in combination with the microDAWN® multi-angle light scattering (MALS) detector to measure absolute molar mass and size of macromolecules and nanoparticles in solution, via µSEC-MALS.

Considering the extremely small peak volumes of UHPLC, band broadening in the microOptilab is kept to the absolute minimum, at less than 4 µL, as compared to 20-40 µL or more from other dRI detectors.


  • dRI noise: 1.5x10-9 RIU
  • dRI range: ±4.7x10-3 RIU
  • Dynamic range: 6,000,000:1
  • Absolute RI sensitivity: ±0.002 RIU
  • Absolute RI range: 1.2 – 1.8 RIU
  • Temperature control: heated/cooled 4 - 65°C, including active stabilization—even at room temperature
  • Wavelength: 660 nm, matched to the microDAWN; other wavelengths available
  • Touch-panel display for immediate access to data, diagnostics and settings


  • Universal online concentration measurement for chromatography, especially µSEC-MALS for absolute molecular weight
  • Analysis of conjugated proteins, co-polymers and nanoparticle-encapsulated drugs/proteins/DNA/RNA when combined with a MALS and UV detector