Optilab T-rEX - Universal Detection for Chromatography and FFF Separations

Unique dRI Detector

The Optilab is a unique dRI detector for standard HPLC/GPC with 256 times the detection power and 50 times the dynamic range of every other RI detector for chromatography in existence today, making it a valuable addition to any MALS setup.

Using a combination of cutting-edge semiconductor photodiode technology and proprietary computer algorithms, the Optilab T-rEX achieves an unprecedented combination of sensitivity and range. These features mean that it addresses both standard chromatographic applications and some challenges unique to light scattering measurements such as high concentrations, determination of sample refractive increments (dn/dc) and solvent refractive index.

Key Benefits

• Extraordinary dRI measurement range, -0.0047 - +0.0047 RIU (comparable to 25 mg/mL protein in PBS)
• Highly sensitive, ±7.5 x 10-10 RIU across the entire measurement range
• Measures solvent absolute refractive index, required for MALS caluclations
• Measures at the same wavelength as the MALS detector, for maximum accuracy in MALS calculations
• Band broadening < 20 µL preserves SEC resolution
• Temperature range 4°C - 65°C for proteins and polymers that require a range of temperatures
• High-resolution, touch-screen front panel displays data graphs and diagnostics, even with the host computer turned off

Unparalleled Features
Even though the Optilab T-rEX offers a dRI measurement range orders of magnitude beyond that of other dRI detectors, unlike other detectors there are no range or gain settings in the T-rEX. The full range of instrument detection is always present, and the full sensitivity exists over the entire range.

The T-rEX can also do something no other on-line refractive index detector can: it can measure the absolute refractive index of a solution. In addition, it can measure the dn/dc of a solvent at the same wavelength of light as the light scattering instrument. And just to make sure it can`t be matched, you can replace the light source in the T-rEX for other wavelengths (e.g., 690, 633, 488, etc.) in just minutes!

The T-rEX can go below ambient temperatures as easily as above ambient. No hassle temperature control can be programmed from 4°C to 65°C. Compatible with all HPLC systems.

Revolutionary dRI detection optics
The Optilab T-rEX inherited the breakthrough optical design of the award-winning Optilab rEX dRI detector which makes use of a 512-element diode array and proprietary algorithms, instead of the usual bi-cell design, bringing dRI detection into the 21st century. The T-rEX added improvements in optical stability, temperature control, LED light source intensity and increased on-board computing power in order to enhance sensitivity and extend the temperature range over the rEX.

Minimal loss of resolution
Each detector downstream of SEC or FFF adds band broadening and dispersion, according to its internal fluidic volume. With a total flow cell volume of only 7.4 µL – 25% less than the leading HPLC refractometers – the Optilab does not impact SEC resolution adversely. This translates into minimized band broadening and better temperature stability.

SEC-MALS and FFF-MALS
An Optilab T-rEX is generally combined with a DAWN HELEOS or miniDAWN TREOS MALS detector for anaysis of molar mass / molecular weight, conformation and conjugation of macromolecules in solution by means of SEC-MALS or FFF-MALS. It also combines with a ViscoStar II differential viscometer for analysis of intrinsic viscosity.

General use
Though its optimal use is in conjunction with MALS analysis, the Optilab T-rEX can be operated downstream of any standard GPC or HPLC system. While ASTRA utilizes its 22+-bit digital signal, it also offers a 18-bit analog output for use with 3rd-party systems, typically when MALS is not utilized.

The Optilab T-rEX offers an unparalleled dynamic range for use as both an online and batch measurement system. For batch measurement, sample is injected into the instrument (usually by means of a WISH Injection Module or Calypso II) in order to measure dn/dc or as part of a CG-MALS interaction analysis.

High Concentration Option
When the primary analysis desired is batch mode, the High Concentration version of the T-rEX is optimal since it extends the range of measurement by sevenfold compared to a standard T-rEX, while losing only a factor of 2 in sensitivity. The High Concentration T-rEX offers measurements up to 180 mg/mL of protein but may still be used in chromatography mode for 99% of all SEC-MALS and FFF-MALS measurements.

• RI Calibration Kit - Pre-made RI calibration standards are available to speed up RI calibration. Can be used to calibrate any Optilab or third-party differential RI instrument.
• WISH Injection Module - The Wyatt Injection System High-Pressure (WISH) is ideal for use with an Optilab dRI detector for the determination of dn/dc in "batch" mode.
• Microbatch Kit - Used to inject samples into the flow cell of a MALS detector, and in determining dn/dc.SysTrack - Convenient shelving for holding multiple detectors in your experimental setup.
• Thermos - A temperature-controlled chamber for SEC/GPC columns and FFF channels.