pE-2 - CoolLED
  • pE-2 - CoolLED
  • pE-Collimator
  • pE-2 Control Pod


The pE-2 is a fluorescence LED illumination system which provides repeatable and controllable light with a choice of 20 different LED peaks. It is perfect for the researcher who has a specific set of tests to conduct. The user can specify a wavelength configuration matched to their particular fluorescence requirements. It is modular, allowing LED wavelengths to be exchanged as requirements vary or additional experiments are added. Manual control is via a remote control pod with instant on/off and intensity control from 0-100%. Additionally, the system is fully integrated under many imaging software packages.

The mercury-free pE-2 LED illumination system is designed for use on most epi-fluorescent microscopes. The output is stable, repeatable and controllable. High intensity light is generated within the pE-2 Light Source and delivered to the microscope via two liquid light guides and a combining collimator. This modular system accepts LAMs (LED Array Modules) selected from CoolLED’s wide range of LED wavelengths. These LAMs can be interchanged by the user so that different LED wavelengths can be illuminated depending on the application. The system can drive up to 4 LED wavelengths. CoolLED LED Wavelength Graph Recent developments in LED technology have enabled increased intensity in what was historically the weaker green-yellow-red (“GYR”) region of the LED spectrum. A new wide spectrum GYR LAM is now available and can readily be fitted to new and existing pE-2 systems. The graph below shows the greater comparative intensity of this LAM over the previous LED wavelengths available for this spectral region. pe-2_02 The system comprises a pE-2 Light Source which powers and thermally controls the LAMs, two liquid light guides, a combining collimator fitted with a microscope adaptor, and a control pod. The collimator includes an exchangeable dichroic mirror which is matched to combine the selected LED wavelengths from each installed LAM. Excitation light can be filtered within the pE-2 system instead of within the microscope so that the need for an excitation filter wheel for dual staining and other fast-switching applications is removed. For this purpose, two filter holders are provided with the collimator. When populated with excitation filters, these can be inserted into the optical path within the collimator. With an expected lifetime in excess of 25,000 on hours and a comprehensive range of LED wavelengths and microscope adaptors, the pE-2 can be fitted to most current and older microscopes and operate for many years without aligning or replacing bulbs. The result is a versatile and configurable fluorescence illumination system without any additional operating costs. For further information go to the Downloads tab

The pE-2 offers:-

  • Modular system which drives up to 4 wavelengths – suitable for all fluorescence experiments
  • Integrated with many imaging software packages – perfect for automation and time-lapse
  • Collimator accepts excitation filters for fast-switching applications – filter wheel not required
  • Instant on/off - no shutters required, no warm up or cool down
  • Simple to fit, simple to use – no alignment, a once only adjustment
  • Stable & repeatable – reliable and consistent results
  • Wide range of microscope adaptors – fits most microscopes
  • Precise intensity control in 1% steps (0-100%) – no ND filters required
  • Excellent uniformity over field of view – fixed and stable, no alignment necessary
  • Long lifetime – expected to exceed 25,000 hours of operating time

Homogeneity +/- 5% variation Stability <0.2% variation over 2 seconds Power requirements 100-240V a.c. 50/60Hz, 1.5A Power consumption

Current in standby when no LEDs are illuminated 7.6W
Single wavelength (565nm) on maximum 2 LED wavelengths in simultaneous on maximum 97W 174W

Dimensions pE-2 Light Source: 140mm(w) x 250mm(d) x 215mm(h) - Weight 5.6kg pE-2 Collimator:  75mm(w) x 143mm(d) x 134mm (h) – Weight 1.16kg pE-2 Control Pod: 95mm(w) x 110mm(d) x 40mm(h) - Weight 0.55kg Environment & Safety LED products are more sustainable and energy efficient than conventional illuminators. CoolLED's products have the following benefits:

  • Mercury-free
  • Energy efficient: 80% less power
  • Long lifetime (25,000 operating hours)
  • No bulb replacements
  • Reduced risk of eye damage
  • Quiet operation
  • No special disposal regulations

Warranty System = 12 months, LEDs = 36 months

Control pod for operation and access to settings and usage history. Manual: Manual control for instant on/off and intensity control in 1% steps from 0–100% Select between sequential and simultaneous illumination of installed LED wavelengths Remote: Interface connections provided are: Ethernet, USB, and TTL. TTL - Direct control is achieved by sending a user-generated TTL signal to the D-type connector on the rear of the pE-2 Light Source. This is suitable for applications requiring fast-switching (microseconds) of wavelengths and short pulse excitation.  The time from an input signal going high to LED at full intensity is 300 microseconds.  An optional breakout box provides a convenient interface. USB - A fully-configured USB connection is also fitted to the rear of the pE-2 Light Source. This allows full remote automation of the pE-2 Light Source with wavelength selection and intensity selected.  Switching time is <10 milliseconds. Ethernet – firmware updates can be downloaded from the website and uploaded via the Ethernet port Imaging Software: Recognised under common software e.g. Micromanager, MetaMorph, cellSens, NIS Elements, ImagePro, etc.

Collimator fits directly to a microscope Specify an adaptor from CoolLED’s range of epi-fluorescent port microscope adaptors Liquid Light-Guide 1.5m long, 3mm diameter.

244-3750-99415-YYY-ZZ:   pE-2 Light Source, two 3mm diameter, 1.5m long liquid light guides, pE-2 Collimator, interchangeable microscope adaptor to customer-specified microscope, remote manual control pod, and power supply.
244-5100-XXX-XXX:   LED Array Module (LAM) at two specified wavelengths
244-5100-GYR:   LED Array Module (LAM) at green-yellow-red (GYR) wavelengths
244-5100-XXX:   LED Array Module (LAM) at single specified wavelength

To specify LED wavelength (XXX) see LED Wavelengths To specify microscope code (YYY) see Adaptors To specify power cable (ZZ): 10 = Australia, 20 = Europe, 30 = UK, 40 = USA

CoolLED pE-2 leaflet CoolLED pE-2 Configuration Diagram Product Videos CoolLED multi-wavelength LED illumination Instruction Videos Optimising light-guides Exchanging LAMs and Dichroic Mirror Excitation filters in the pE-2 collimator

244-5100-XXX-XXX   LED Array Module (LAM) at two specified wavelengths
244-5100-GYR   LED Array Module (LAM) at green-yellow-red (GYR) wavelengths
244-5100-XXX   LED Array Module (LAM) at single specified wavelength
244-4312-410   Dichroic mirror for the pE-2 Collimator at 410nm
244-4312-455   Dichroic mirror for the pE-2 Collimator at 455nm
244-4312-490   Dichroic mirror for the pE-2 Collimator at 490nm
244-4312-515   Dichroic mirror for the pE-2 Collimator at 515nm
244-4312-XXX   Dichroic mirror for the pE-2 Collimator at XXXnm (request cost)
244-4325-25   Excitation filter holders for the collimator (2 off). Accept 25mm diameter filters
pE-10400:   pE-Universal Collimator for use with a single liquid light guide. Requires additional microscope adaptor
pE-ADAPTOR-YYY   Microscope adaptor to user-specified microscope
244-10000    pE-Breakout Box - connects to pE-2 Light Source (15-pin D-type) and has 4 BNC out ports + TTL trigger
244-66-YYY   pE-Dual Adapt – Fit CoolLED system and 2nd (Hg, metal halide etc.) illuminator to epi-port of microscope


"Following comparative testing, we selected CoolLED's LED systems. Intensity, ease of control, and integration with our selected imaging software, were the reason for making this selection. We now have 12 CoolLED systems and plan more in future. We like CoolLED's flexible approach and found the company to be responsive and supportive". Pawel Pasierbek, IMP, Vienna "We have recently established a visualisation process for small GTPase activity using FRET. We used a CoolLED pE-2 LED system to excite the fluorophores. It proved to be an essential tool in the acquisition and processing of the FRET images by (inter alia) its ability to minimise photo-bleaching". Kazuhiro Aoki & Michiyuki Matsuda, School of Biostudies, Kyoto University "I work on experimental epi-fluorescence systems using a novel objective lens of low magnification and high N.A. I have found the CoolLED pE-1 illumination system extremely useful and convenient, particularly because I need precisely constant power over both milliseconds and hours, and I can work much faster if there is no warm-up problem. I have also found the company very helpful". Brad Amos. LMB, Cambridge "We now have a number of CoolLED LED systems. The most recent has been fitted to a live cell imaging system which was rarely used. Now that users have realised how stable the light source is and how easy it is to control a CoolLED system, the microscope is used almost full time. This is a great use of lab resources where a small investment in a light source has renewed a microscope system". Peter March, Faculty of Life Sciences, Manchester University "We have had great success using the CoolLED system for high speed imaging of fluorescent protein pairs ECFP/EYFP and EGFP/dsRed. We get consistent results at speeds not possible with bulb and shutter/ filter wheel systems". Jens Rietdorf, Friedrich-Miescher Institut / Novartis, Basel "We have a CoolLED LED unit on a simple tissue culture microscope that is used by many people. The unit is perfect in this situation because it is aligned only once, very simple to use, instantly on or off, controllable, doesn't require a PC to control it, doesn't get hot and there's no bulb to fail at an inconvenient time. It won't take up any of my time in the future - which is perfect! I can happily leave the unit in a tissue culture suite knowing that there are no safety or maintenance issues". Paul Appleton, Cell & Developmental Biology, Dundee University "We perform quantitative ratio imaging in living cells. The most appealing performance characteristics of the CoolLED LED excitation system for us are: very good stability of light intensity, essential for quantitative work - no arc wandering, fluttering or flaring issues, fast vibration free switching of wavelengths, suitable for live cell imaging (no unintentional UV exposure), easy adjustment of light intensity to reduce photo bleaching and photo toxicity, and controllable via imaging software packages". Harri Mustonen, Department of Surgery, Helsinki University Hospital "We have a CoolLED system on a fixed stage microscope equipped for patch-clamp recordings in slices. This illumination system is ideal for combining live cell imaging with electrophysiological recordings. Indeed, for this application, where mechanical and light intensity stability are crucial, the fast vibration free switching of wavelengths of the CoolLED system offer a considerable advantage over conventional light sources." Bruno Cauli, Universite Pierre et Marie Curie, Paris