Application Note

Gemini XPS Microplate Reader

  • No filters needed
  • Higher sensitivity
  • Validation tools
  • Robotics compatible

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The Gemini XPS Microplate Spectrofluorometer from Molecular Devices provides a flexible environment to determine the optimal excitation and emission settings for most fluorescent intensity assays. The Gemini XPS Reader has dual monochromators that allow users to utilize new and novel dyes without purchasing expensive filter sets. SoftMax® Pro Software, included with every Gemini XPS Reader, provides convenient data analysis. The optional SpectraTest® FL1 Validation Plate automatically validates the performance of the reader. Software validation, IQ/OQ/PQ and FDA 21 CFR Part 11 compliance tools are also available.

Dual monochromators

With the Gemini XPS Reader, users don’t have to worry about having the right set of filters. The system uses two scanning monochromators to determine the optimal excitation and emission settings. Assays vary depending on temperature or pH conditions; the monochromators allow users to select the optimal wavelength for any assay. Alternatively, literature values for the monochromator can be easily entered. When methods or fluorophores change, it takes only a few software commands to adjust the reader.

Well Scanning

With well scanning, multiple points within each well can be read, providing a high level of sensitivity for cell-based assays. Endpoint, kinetic and spectrum scanning assays can also be run.

Plate stacker and robot integartion

The Gemini XPS Reader can be integrated with Molecular Devices’ StakMax® Microplate Stacker in a matter of minutes and begin reading microplates with seven mouse clicks. For a higher degree of automation, the Automation Vendor Partners Program has streamlined the integration of our microplate reader systems with all leading partner robots. The “out-of-the-box” automation solution saves up-front integration time and resources.

Leading data analysis software

SoftMaxt Pro Microplate Data Analysis Software provides flexibility in experimental design, setup, analysis and reporting, providing the opportunity to customize assays. Choose from nine different curve-fitting routines and use default data reduction, or set up custom formulas for analysis. Data can be analyzed and combined from different plates.


Live/Dead viability/cytotoxicity assays

Detection of nucleic acids

Green fluorescent protein

NanoOrange protein quantitation

PicoGreen DNA detection

Molecular beacons


Fluorometric protease assays

cAMP detection

Technical specifications

Fluorescence Photometric Performance

Dual monochromators: 1 nm increment selection
EX wavelength: 250–850 nm
EM wavelength: 360–850 nm
Bandwidth (EX, EM): 9 nm
Detection limit (signal 3X SD of baseline): 3.0 fmol/well FITC 200 µL in 96 wells

Time-Resolved Fluorescence (Secondary Mode)

Wavelength range: 360–850 nm
Data collection: 50–1450 µsec., 200 µsec. increments
Sensitivity: 0.5 fmol/well Eu-chelate (obtained with DELFIA reagent from Perkin Elmer by using a 384-well plate)

Luminescence (Secondary Mode)

Detection limit: 10 amol/well alkaline phosphatase 200 µL/well (obtained with Emerald II reagent from Applied Biosystems)

General Photometric Performance

Plate formats: 6, 12, 24, 48, 96, 384 wells
Light source: Xenon flash lamp (1 joule/flash)
Detector: Photomultiplier (R-3896)
Read time*: 96 wells in < 15 seconds 384 wells in < 45 seconds
Shaker time: 0 to 999 seconds
Temp. control: 4°C above ambient to 45°C

* Measurement type may extend read time

General Specifications

Dimensions (in.): 8.6 (H) x 22.8 (W) x 15 (D)
Dimensions (cm): 22 (H) x 58 (W) x 38 (D)
Weight: 35 lbs. (15.9 kg)
Power consumption: < 125 watts
Power source: 100–240 Vac, 3 A, 50/60 Hz
Robot compatible: Yes

Ordering information

Contact your Molecular Devices sales representative for configuration options.

Sales offices

USA & Canada +1-800-635-5577

Brazil +55-11-3616-6607

China (Beijing) +86-10-6410-8669

China (Shanghai) +86-21-6887-8820

Germany +49-89/96-05-88-0

Japan (Osaka) +81-6-6399-8211

Japan (Tokyo) +81-3-5282-5261

South Korea +82-2-3471-9531

United Kingdom +44-118-944-8000

Check our web site for a current listing of our worldwide distributors.


The trademarks used herein are the property of Molecular Devices, Inc. or their respective owners.

Specifications subject to change without notice.

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