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The high throughput screening gold standard that features the highest sensitivity and fastest read times available

The PHERAstar FSX was designed so that all the most common detection technologies can be performed with the best possible sensitivity. Regardless of your read mode; fluorescence, luminescence, fluorescence polarization, time resolved fluorescence, absorbance, or AlphaScreen, you can be confident in your results even when reading a plate in HTS flying mode.

The excellent performance of the PHERAstar FSX extends to reading modes that employ simultaneous dual emission (SDE) detection such as FRET, fluorescence polarization, BRET, NanoBRET, AlphaPlex, and HTRF as well as other TR-FRET technologies. Even in absorbance reads the PHERAstar FSX excels with a UV/Vis spectrometer that can collect multiple wavelengths or the entire spectrum from 220-1000 nm in under one second per well.

The PHERAstar FSX is the fastest and most sensitive high-throughput screening plate reader on the market. Schedule a demo in your laboratory and see how the PHERAstar FSX will make the most of your assay.


  • Four PMTs for optimal detection and superior speed
  • Three excitation sources; Xenon flash lamp, HTRF laser, AlphaScreen laser
  • UV/vis spectrometer for instant spectral capture
  • Direct optics for high sensitivity reading from the top or bottom of the microplate
  • Assay specific modules; all modules can be used for top or bottom reading
  • Reagent injection-featuring reading at point of injection
  • High density well scanning – up to 900 points / well
  • Compatible for any robotic integration platforms
  • Control software is 21 CFR compliant
  • MARS data analysis with programmable ASCII export
  • LVis Plate and Stacker compatible


  • MycoAlert Ready Device
  • Transcreener Far RedFP Validated
  • Transcreener Red TR-FRET Validated
  • Transcreener RedFI Validated
  • HTRF Compatible
  • LanthaScreen Certification Plus
  • DLReady

At the core of the PHERAstar FSX’s unmatched performance are the two pairs of matched photomultiplier tubes (PMT’s) which are optimized for different reading modes. One pair of PMT’s is optimized for low-light assays such as TR-FRET/HTRF technologies, while the other pair is used for prompt fluorescence and other assays. The matched PMT’s are essential for simultaneous dual emission (SDE) detection. With this multi-PMT’ detection system you’ll not only get faster results in FRET, FP, BRET and TR-FRET, they will also be better than what you are accustomed to seeing.

For excitation of most detection technologies the capabilities of the high intensity xenon flash will be outstanding. For some advanced technologies this excitation source will be adequate, but with the PHERAstar FSX there is no need to settle for good enough. You can add a UV laser for excitation of TRF and HTRF, as well as other TR-FRET technologies, thus improving limits of detection, Z’ values and read times. Similarly, an Alpha technology laser at 680nm is a perfect addition to improve your AlphaScreen and AlphaLISA assay performance. With these three excitation sources you will always have the right choice for your assay.

The PHERAstar employs assay specific modules for each detection mode. These modules are barcoded to indicate to the software which capabilities are enabled and describe the optical characteristic of the module to the reader. You need never worry again about whether you have the right filters, dichroic mirrors, beamsplitters, or polarizers in place as they are all contained in the optic module. Also, because of the free-air optical design which was introduced in the PHERAstar line, any optic module can be used for bottom reading. All of the switching between detection capabilities, excitation sources and top or bottom reading is controlled automatically. All you need to do is make the selection in the software.

Detection Modes 

Fluorescence Intensity
Fluorescence Polarization
High-end AlphaScreen®/AlphaLISA®
Luminescence (flash and glow)
UV/Vis absorbance spectra

Measurement Modes 

Top and bottom reading
Endpoint and kinetic measurements
Sequential Multi Excitation measurements
Sequential Multi Emission measurements
Simultaneous Dual Emission measurements
Spectral scanning (absorbance)
Real-time ratiometric measurements
Well scanning

Microplate Formats 

Up to 3456-well plates, user-definable
LVis Plate with 16 low volume microspots (2 μL)

Microplate Carrier 

Robot compatible

Light Sources 

High energy xenon flash lamp
Dedicated Laser for AlphaScreen® / AlphaLISA®
UV Laser for TRF / TR-FRET / HTRF


Four photomultiplier tubes, optimized for different detection modes
CCD spectrometer

Wavelength Selection 

Optic Modules: Up to six application-specific modules (includes all filters, dichroics, etc. for an application)
One module is used for top and bottom reading
UV/Vis Absorbance Spectrometer: Full spectra or 8 distinct wavelengths in < 1 sec / well

Optical Path Guides 

Top and Bottom: Enclosed, free-air optical light path guided by motor-driven mirrors and dichroics


Automatic focal height adjustment (0.1 mm resolution)

Spectral Range 
Filters 230 – 750 nm or 230 – 900 nm for FI, FP
230 – 750 nm for LUM
230 – 900 nm for TRF
Spectrometer 220 – 1000 nm for ABS
FI (top) < 0.4 pM (< 8 amol/well Fluorescein, 384sv, 20 μL)
< 2.0 pM (< 6 amol/well Fluorescein, 1536, 3 μL)
FI (bottom) < 1.0 pM (< 50 amol/well Fluorescein, 384g, 50 μL)
FP < 0.5 mP SD at 1 nM FITC 384sv black, 20 μL
< 1.5 mP SD at 1 nM FITC, 1536 black, 8 μL
TRF < 5 fM (< 0.1 amol/well Europium, 384sv)
< 15 fM (< 0.13 amol/well, Europium, 1536, 8 μL)
(black and white
Reader Control Kit (Eu) after 18h (384sv, 20 μL)
Delta F > 1100 % (High Calibrator)
Delta F > 25 % (Low Calibrator)
LUM < 0.4 pM (< 8 amol/well, ATP, 384sv, 20 μL)
with Laser
< 5 pM (< 100 amol/well P-Tyr-100, 384sv, 20 μL)
with Spectrometer
Full spectrum captured in < 1 s / well
Selectable spectral resolution: 1, 2, 5, and 10 nm
OD range: 0 – 4 OD
Accuracy: < 1% at 2 OD
Precision: < 0.5% at 1 OD and < 0.8% at 2 OD
Read Times 
Flying mode
(1 flash)
14 s (384)
27 s (1536)
10 flashes 38 s (384)
1 min 52 s (1536)
50 flashes 1 min 29 s (384)
5 min 18 s (1536)
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

Integrated Barcode Reader 

Up to three integrated barcode readers


+5 °C above ambient up to 45 °C


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


Width: 45 cm, depth: 51 cm, height: 47 cm; weight: 49 kg

LVis Plate (Optional Accessory) 

Sample Capacity: Sixteen separate microdrop wells for 2 µL samples; One standard cuvette position for up to 1 mL samples.
Quality Control Internal Standards (optional): Four NIST traceable optical density filters (approximate values of 0.1, 0.3, 0.6 and 1.0 OD); One holmium oxide filter for wavelength accuracy.
Dimensions: Conforms to SBS standards for microplates.


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.


LOD = 3 x SD (20 blanks) / slope (6 pt std curve)
AlphaScreen® P-Tyr-100 assay kit, PerkinElmer, #6760620C
Microplates: white for LUM, AlphaScreen®, TRF; black for FI, FP; clear for ABS
384sv = 384-well small volume microplates
384g = 384-well glass bottom microplates
1536 = 1536-well microplates