Products & ReviewSeparations


Waters | Wyatt TechnologyWTREX / WTRXHAvailable: Worldwide

The Optilab™  is a unique dRI detector for HPLC/GPC, optimized for use with MALS.

Request Pricing
Waters | Wyatt Technology

Receive your quote directly from the manufacturer.

Average Rating 4.8

|7Scientists have reviewed this product

Ease of Use
After Sales Service
Value for Money
Write your own review

Optilab T-rEX is a reliable and easy to use refractive index detector.


Average Rating 4.7

Application Area:

Protein chemistry

Optilab T-rEX is our refractive index detector online with the HPLC system and miniDAWN TREOS II 3-angle light scattering detector. We use the above system to characterize recombinant proteins, e.g. their in-solution homo- and heteromultimerization properties, and conjugation to carbohydrates or nucleic acids. In the latter application, the Optilab T-rEX is a seminal piece of the analytical pipeline, and overall provides us with an efficient means to measure concentrations in all of our SEC-MALS applications. The use is straightforward with our protein core personnel, and also with external users after we have trained the operating person. The instrument has been extremy reliable.

Review Date: 11 May 2022 | Waters | Wyatt Technology

This instrument is very helpful and workable.


Average Rating 4.0

Application Area:

Molecular weight of polymers

To directly determine the molecular weight is a difficult job to work on. This instrument enabled my lab to easily determine the molecular weight of starch, cellulose, and chitin with reliable data. The operation of the instrument needs some training, and fundamental understanding on the measurement principles. I used the SEC/MALLS/RI analysis system comprising a SEC system (1260 Infinity, Agilent), a multi-angle laser light scattering (MALLS) detector (DAWN HELEOS-II, λ = 658 nm, Wyatt Technology), and an RI detector (RI, Optilab T-rEX, Wyatt technology).

Review Date: 7 Mar 2020 | Waters | Wyatt Technology

One of the best analytical instruments I ever used in my 25 years working.


Average Rating 5.0

Application Area:

Molecular weight analysis for depressants. Together with the LS detector we are able to do conformat

As we were starting characterization of our polymers depressants and collectors, we needed to get instruments that will give us most information for us to understand how each property will affect the quality and performance of our product, as part of continuous improvement. We bought the Wyatt triple detectors of which RI was one of them. The service we got from the company was very good starting from installation of the instruments. Doing operational qualification and performance qualification of the detectors was excellent. They sent a professor to help us with that training on the system for data analysis. After sale care was also excellent - when we had just started we had problems in understanding some information and data we got from the systems. We sent all the information to Wyatt head office and within 24 hours we got response. When one of the detectors had a breakdown we shipped to the US and within a very short time it was back working properly.

Review Date: 28 Sept 2018 | Waters | Wyatt Technology

Used daily in our lab- we consistently rely on it!


Average Rating 5.0

Application Area:

Measure concentration of downstream SEC samples

The Optilab T-rEX is the perfect complement to the DAWN HELEOS II to supply reliable and accurate concentration information for molecular weight measurements. Having an RI detector in our flow path is also quite handy if our samples have weak or no UV absorbance.

Review Date: 20 Dec 2016 | Waters | Wyatt Technology

I could not recommend Wyatt Technology more highly!


Average Rating 5.0

Application Area:

Analysis of Molecular Weight Distribution in Linear Polysaccharides

Highly sensitive and reliable system that provides exceptional accuracy and precision. Sales support at Wyatt is one of the best in the analytical instrument sector.

Review Date: 29 Jul 2016 | Waters | Wyatt Technology

This instrument is invaluable in our lab.


Average Rating 4.7

Application Area:

Characterization of Polymers for Paint and Coatings Applications

The T-rex has given our lab a powerful tool in characterization of unknown polymers. We have been successfully characterizing raw materials, unknowns, and problem batches for our company for over a year now. We now can also get accurate polymer MW and distribution data where before we could only compare to standards (usually a dissimilar polystyrene). The system does require a relatively skilled person to perform analyses, but Wyatt also paid for training! Every time I have needed any help the highly trained Wyatt staff have answered questions very quickly. The support is wonderful.

Review Date: 24 Jun 2016 | Waters | Wyatt Technology

Each SEC/GPC Lab has to have at least one set-up.


Average Rating 5.0

Application Area:

Polymer analysis

Easy to use equipment. Always can rely on help from Manufacturer network. Reliable results and very good reproducible. The set-up works 24/7/365.

Review Date: 24 Jun 2016 | Waters | Wyatt Technology

The Optilab™ differential refractive index (dRI) detector may be used in conjunction with any HPLC, FPLC, GPC or FFF separation system, plus a Wyatt DAWN™ or miniDAWN™ multi-angle light scattering (MALS) detector, for the absolute determination of the molar mass of all types of macromolecules in solution. While its sensitivity matches the very best HPLC RI detectors, its dynamic range exceeds that of any comparable instrument by 10-100x, with no range settings - meaning you can characterize very large and very small peaks, simultaneously.

In addition to dRI, the Optilab™ also measures the absolute refractive index (aRI) of a solution, important for characterizing solvents. The high-concentration (HC) model provides an extended measurement range suitable for high-concentration samples (up to 180 mg/mL of protein) or gradient-elution chromatography such as ion-exchange.


  • dRI noise: 7.5x10-10 RIU (HC model: 1.5x10-9 RIU)
  • dRI range: 4.7x10-3 RIU (HC model: -2.6x10-3 to +34x10-3 RIU)
  • Dynamic range: 12,000,000:1 (HC model: 23,000,000:1)
  • 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 MALS instruments; other wavelengths available
  • Touch-panel display for immediate access to data, diagnostics and settings


  • Universal online concentration measurement for chromatography, especially SEC-MALS and FFF-MALS.
  • Analysis of conjugated proteins, co-polymers and nanoparticle-encapsulated drugs/proteins/DNA/RNA when combined with a MALS and UV detector
  • Offline measurement of second virial coefficient A2 (B22)
  • Offline measurement of the specific refractive index increment dn/dc, at the same wavelength as the MALS laser (critical for accurate macromolecular characterization)
  • Ion-exchange chromatography with MALS (IEX-MALS) – measure dRI over the entire salt gradient
  • Composition-gradient MALS (CG-MALS) – measure protein-protein interactions at high concentration

Product Overview