CoolLED’s pE-300white offers intense, broad-spectrum LED illumination for fluorescence microscopy that is perfect for hospital and regular research laboratory environments. The system is a mercury-free alternative that is safer, more controllable and precise than traditional bulb illumination options.  Spectral coverage is from the UV (DAPI excitation) to the red region (Cy5 excitation).

LED technology is quickly evolving, and since 2017 our new generation has double the irradiance at the sample plane, and for even higher irradiance is available as a Direct Fit model (which also reduces the cost to buy and run thanks to fewer consumables). With ACT Label certification, it’s even an environmentally friendly option for illumination.

pE-300 Series Normalised Spectrum Graph Aug 2023

The pE-300white is a compact and simple to use LED illuminator for microscopes.  It provides a broad spectrum of illumination, covering the excitation bands of common fluorophores such as DAPI, CFP, Aqua, FITC, TRITC, TxRed, Cy5 and many more.  Operation is by a manual control pod with instant on/off and irradiance control from 0-100%, with remote control available via USB or TTL trigger.

Direct fit or liquid light guide

There are two pE-300white configuration options: direct fit or liquid light guide. The direct fit variant delivers higher irradiance and reduces the cost to buy and run thanks to fewer consumables.

Comparing Irradiance Between Direct Fit and Liquid Light Guide Illumination Systems

For confocal microscopes, the liquid light guide variant offers the ideal replacement to a metal halide light source, minimising photobleaching and phototoxicity when viewing samples before scanning. More information on the available variants can be found under specifications.

Fast multi-channel imaging

An additional benefit of the pE-300white is that fluorophores can be viewed either individually or in combination, without filter cube changes.  This makes it ideal for use with multi-band filter sets as the screening process can be simplified when fewer filter cubes are used.  Independent control of the three LED wavebands allows control of the level of excitation of each fluorophore independently on a multi-stained sample, potentially removing the need for single-band filter sets altogether.

Energy efficiency for cost-saving sustainability

When it comes to making labs safer and more sustainable, LED microscope lighting is an attractive option when compared to old toxic mercury or metal halide lamps. All three channels of the pE-300white at full power use just 60 Watts, which is even lower than other LED technology which uses 120 to 350 Watts. “Green Grants” are even sometimes available from establishments, providing financial support owing to the reduction in institutional energy usage.

Award winning technology

CoolLED’s pE-300 Series was the 2017 winner of the International Institute for Sustainable Laboratories (I2SL) “Go Beyond Award” for “Excellence in sustainability in laboratory and other high technology facilities”.

  • Remote control via USB or TTL trigger
  • Clean bright illumination across the spectrum: excites common fluorophores
  • Three LEDs
  • Instant on/off: No shutters required, no warm up or cool down
  • Stable and repeatable: reliable and consistent results
  • Precise irradiance control in 1% steps (0-100%): no ND filters required
  • Specify for existing single and multi-band filter sets: no need to buy new filters
  • Simple to fit, simple to use: no alignment, a once only adjustment
  • Wide range of microscope adaptors: fits most microscopes
Plus all the benefits of LED technology

The system comprises a pE-300white Light Source, control pod, and power supply.


Control pod for operation and access to settings and usage history.

Manual control for instant on/off and irradiance control in 1% steps from 0 – 100%
Individual bands can be selected/deselected and controlled independently as desired

Via single TTL for on/off control of selected channels using a BNC connection on the light source.
Triggering speed <20 µs

Remote via USB (B type) for imaging software control (see Imaging Software)


There are several variants available, as explained below:

Choosing configurations

There are two pE-300white configuration options:

Direct Fit: Higher irradiance is possible when directly connecting to a microscope. Select from a range of microscope adaptors which covers all current and most older models.  A simple once-only adjustment will allow optimisation to the optical path of the microscope.

Liquid Light Guide: If there is a need to keep the source of illumination remote from the microscope. As a replacement to a metal halide source on a confocal microscope, the liquid light guide configuration is particularly suitable for pre-aligning samples before scanning commences.  In this way, photo bleaching of the sample can be minimised when LED illumination is used. This requires a fixed 3 mm diameter liquid light guide.  An optional pE-Universal Collimator can be specified in conjunction with a microscope adaptor if required.  We now include a light source stand for the pE-300white Illumination Systems ordered for light guide delivery.

Choose single-band or multi-band

DAPI can be excited at either 365 nm or 400 nm and microscopes typically have a filter set which allows one or other of these wavelengths to be transmitted.  To accommodate this, the pE-300white can be specified in one of two waveband configurations to match existing filter sets within the microscope.

A microscope which is populated with a number of single band (“SB”) filter sets will typically have DAPI excitation at 365 nm and a microscope with multi-band (“MB”) filter(s) has excitation at 400 nm.  The user can specify the configuration which is appropriate for their microscope.


Power requirements
100-240 V a.c. 50/60 Hz

Power consumption

pE-300 Series At the wall (includes power supply unit consumption)
Standby 3.3 W
1 band (GYR) 24.4 W
2 bands (BLU & GYR) 44.3 W
Full white irradiance (3 bands) 56.4 W


pE-300white Light Source: 77 mm(w) x 186 mm(d) x 162 mm(h) – Weight 1.4 kg
pE-300white Control Pod: 88 mm(w) x 125mm(d) x 37 mm(h) – Weight 0.32 kg
pE-300white Power Supply: 167 mm(w) x 67 m(d) x 35 mm(h) – Weight 0.62 kg

pE-Universal Collimator: 44 mm(w) x 86 mm(d) x 44 mm(h) – Weight 0.17 kg

Environment & Safety
  • Mercury-free & Laser-free
  • Energy Efficient
  • Long lifetime
  • No bulb replacements
  • Reduced risk of eye damage
  • Quiet operation
  • No special disposal regulations or issues

Industry-leading 36 months. Read more here.

All data correct at time of publication

pE-300 Series Normalised Spectrum Graph Aug 2023
pE 300 Series MB Spectrum
pE 300 Series SB Spectrum

We are often asked about the power, intensity or irradiance of CoolLED Illumination Systems. The answer is not as simple as you might believe from many websites and data sheets, and it can be difficult to compare data from these sources as measuring set ups differ.

Photons are also lost as light travels from the light source to sample plane. The only way to objectively compare light sources is by measuring irradiance at the sample plane.  To understand why we use the term irradiance and how to measure and compare light sources with accuracy and precision, download our white paper. Or please contact us if you have further questions.


For performance data, please contact us

CoolLED designs and manufactures LED illumination for microscopy and is ideally placed to deliver OEM illumination requirements.
  • Streamlined development using proven off-the-shelf technology
  • Professional expert support
  • Market-leading warranty
  • ‘Try before you buy’ option
  • Trusted experts in LED illumination technology since 2006

The pE-300white is available in the Amora Series: our proven off-the-shelf product range adapted to offer unparalleled customisation opportunities.

Click the button to find out more.

The scientific community is driving change across academia, industry and government to make laboratories more sustainable. When it comes to fluorescence microscopy illumination, switching to the pE-300 Series can help laboratories meet their sustainability targets, by consuming less energy and avoiding the use of toxic mercury.

Our CoolLED pE-300 Series is also ACT label certified, which stands for accountability, consistency and transparency. Introduced by My Green Lab, this provides an easy way for scientists to measure and compare the environmental impact of a product by reviewing the product itself, its manufacturing process, packaging and disposal. Visit our environment page to find out more.


“It’s great to see how My Green Labs and CoolLED are helping to move things ahead in the area of laboratory sustainability”. – Todd Lynch, UCLA Capital Programs

  • Thank you all for your helpful support, prompt assistance and good communication - and also patience and understanding as we dealt with some administrative delays on our side.  I wish all companies had a support team as good to deal with as CoolLED!

    Suzanne Crotty MSc, Senior Technical Officer, BioSciences Imaging Centre, BioSciences Institute, University College Cork, Ireland (CoolLED Support)

  • We were looking for a cost efficient light source for epi-fluorescence for basic cell biology application. We bought the CoolLED pE-300white. It is not only a very cost efficient solution compared to other LED-based illuminators but also a superior performance. The next light source will be for sure from CoolLED.

    Dr Tim Kaminski, In Singulo Solutions AB (pE-300white)

  • We have been using the pE-300white  for several months now. This unit is amazing, and our technicians love the ease of use. From installing it to the ability to isolate light channels with a push of a button, has made out lives easier. The unit takes up less space than mercury burners, you don’t have to worry about the burner lifespan, and the heat produced by mercury burners. This unit is compact and the control box has a small footprint to maximise space around work area. If you haven’t tried this light source, you need to.

    Ken Reese, VP Laboratory Management, BrainBits, LLC (pE-300white)

  • All our lab members have been very glad that the microscope representative recommended CoolLED pE-300white to us. It is really cool! With this new and award-winning technology, we got rid of the big and heavy fluorescence power supply box and camera controller, and will never worry about the life time of a fluorescence lamp again, because we can use the pE-300white almost forever. Now we can turn the fluorescence on or off instantly and adjust the intensity precisely and conveniently with no shutters required. In addition, the illumination is clean, bright and stable across the spectrum, and it is not just safer for us but also energy-efficient for our environment. We love it! Thank you, CoolLED!

    Dr Tian Luo, Research Scientist, University of Texas Medical Branch (pE-300white)

  • CoolLED Illumination Systems are fantastic, and I really want to highlight how easy they are to use, which is great from a training perspective. In terms of microscopy, the flexibility of selecting and tuning individual channels is beneficial to prevent photobleaching.  LED microscope lighting has improved so much in the last few years, and every layer of extra capability makes the microscope setup more interesting to use.

    Alfonso Schmidt, Bioimaging Specialist, Hugh Green Cytometry Centre, Malaghan Institute of Medical Research (pE-300 Series)

  • The introduction of CoolLED Illumination Systems into the laboratories where I have worked has improved the use of standard light microscopy and also fluorescence microscopy. Standardised light sources to the specific wavelengths required provides the technician with the confidence to be able to provide high quality and reproducible results.

    Collette Allen, Salisbury NHS Trust, United Kingdom (pE-300white)

  • The unit is impressive compared to the previous mercury bulb set up we’ve been using.

    Simon Marshall, Laboratory Manager Carmarthen Veterinary Investigation Centre (pE-300white)

  • We find the system to be excellent, it gives us bright fluorescence and being able to switch the light on and off without having to worry about warming up/cooling down is a big advantage over our old system.

    Dr Kat Millen , Lab Manager , University of Cambridge, United Kingdom (pE-300white)

  • We’ve just bought the CoolLED pE-300white, the little brother to the pE-4000 (on the confocal, we don’t need the more powerful version), it’s really nice.

    Dr Martin Spitaler, Head of Imaging Facility, Max Planck Institute of Biochemistry, Germany (pE-4000)

  • We are extremely happy with our CoolLED pE-300white System. Integration with our microscope was simple, and the robust system has never needed maintenance or alignment. I am particularly happy with the user interface as it is simple and intuitive.

    David Inglis, Senior Lecturer, Dept of Engineering, Macquarie University, Australia (pE-300white)

  • I just signed off on the installation of our new CoolLED pE-300white,  fitted today on our Leica SP5 confocal. Happy to see the Hg bulb made obsolete! I love it and I’m sure the users will too.

    Rosey van Driel, Manager for Transmission Electron Microscopy (TEM), Institute for Frontier Materials, Deakin University, Australia (pE-300white)

  • The pE-300white has been a great asset for a core facility. It has meant less time spent changing bulbs (so less downtime to the user and more productive time for ourselves) and no longer worrying about users turning the light source on and off throughout the day as multiple users come and go.  The controllable intensity has also proved highly popular with users who are now able to set the minimum light level required to scan their samples and minimise the risk of phototoxic damage and bleaching to their specimens.

    Peter O'Toole, Head of Imaging & Cytometry - University of York (pE-300white)

  • Our imaging facility houses a range of different confocal microscopes from major vendors such as Olympus, Zeiss and Nikon.  All of these systems, including one purchased last year, were supplied with either a mercury arc burner or metal halide light source, used for observation of samples by eye prior to imaging using the confocal laser scanning system.  These light sources suffer many shortcomings, such as the requirement to frequently replace expensive components (burners, light guides), the need for heating/cooling cycles when turning on and off, safety issues regarding risk of explosion and problems with the disposal of mercury-containing bulbs.  For these reasons we decided to replace all of our confocal epi-illuminators with the CoolLED pE-300white.  Users now have the benefit of immediate on/off with no requirement for warm-up/cool-down cycles, they can fine-tune the intensity of illumination to match their labelling, there is no risk of explosion and there are no problems with the disposal of mercury-containing components.  We have found the CoolLED pE-300white to be highly reliable, simple to operate and work very well with all the standard fluorophores we use including DAPI, Alexa fluor 488, Alexa fluor 568.  To my knowledge there have been no instances where the LED light source has been judged inferior to the illuminator it replaced, with most users appreciating the benefits.  As a facility, the decision to replace our epi-illuminators with LEDs was seen as an investment that should be recovered within three years, with the projected lifetime of the LED illuminators considerably exceeding this time.

    Simon Walker, Imaging Facility Manager - Babraham Institute (pE-300white)

  • The CoolLED pE-300white is the perfect fluorescence illumination system for teaching bio-medical students.  It is not only bright enough, but the ability to simultaneously illuminate 3 fluorescent proteins means students can observe structures with better context therefore achieving a more efficient learning outcome.

    Urs Ziegler, Ph.D. Head of Center for Microscopy and Image Analysis, University of Zurich (pE-300white)

  • The lamp is on the microscope and is really impressive. A great product!

    Viki Allan, Professor of Cell Biology, University of Manchester (pE-300white)

  • The CoolLED pE-300white is a perfect fluorescence illumination system for fixed fluorescence samples. We used it on a Nikon E400 upright microscope with four fluorescence channels. With a triple-band filter, it can also be used for simultaneous illumination of three fluorescent proteins. As a system running in a microscope facility, it provides excellent flexibility, enough brightness in all bands to most samples, and is cost-effective, stable, trouble-free, and easy to operate

    Dr. Yan Gu, Manager, Analytical and Quantitative Light Microscopy Facility, Genome Damage and Stability Centre, University of Sussex (pE-300white)

  • We are absolutely delighted with the pE-300white light source - it is fabulous. We use it as illumination on our Zeiss Axioskop to basically just identify the objects of desire for further analysis with laser scan of our confocal system. The CoolLED pE-300white has replaced our old and worn out mercury lamp - we love it for its simplicity in use, and even more for its really bright illumination. Before we had to guess the objects, now we can see them clearly. What a difference!

    Prof. Dr. A. Preiss, University of Hohenheim (pE-300white)

  • Our customer required a fluorescence light source for their new microscope and had enquired about a metal halide light source unaware of the CoolLED pE-300 Series. Once we had demonstrated the pE-300white they were immediately impressed with its capabilities. The ability to control the intensity of the light and the fact that it does not involve changing bulbs were major attractions. Through their work with mosquitos they hope to reduce the spread of diseases such as malaria. To do this they need to be able to clearly see which mosquitoes are fluorescing and the CoolLED pE-300white provides perfect excitation.

    Alan Todd, Microscope Services  Ltd, UK (pE-300white)

The CoolLED Control Pod

The CoolLED Control Pod

CoolLED Multi-Wavelength LED Microscopy Illumination

CoolLED Multi-Wavelength LED Microscopy Illumination

ACT Label

ACT Label

Configuring Volocity

Configuring Volocity

Making use of CoolLED adaptors

Making use of CoolLED adaptors

Installing a pE-300 Series Illumination System

Installing a pE-300 Series Illumination System

Configuring cellSens

Configuring cellSens

Choosing an SB or MB model

Choosing an SB or MB model

Configuring LAS X

Configuring LAS X

Configuring Hamamatsu HCImage

Configuring Hamamatsu HCImage

Configuring MetaMorph

Configuring MetaMorph

Configuring µManager

Configuring µManager

pE-300 Series fit and optimise

pE-300 Series fit and optimise

Shining a light on the pE-300 Series

Shining a light on the pE-300 Series

CoolLED Optimised filters

CoolLED Optimised filters

Using Optogenetics to Analyse Neuronal Circuits

Using Optogenetics to Analyse Neuronal Circuits

Light SourceApplicationTypeCoolLED LEDChromaSemrock
pE-300white SB, pE-300white MBFluorescenceSingle365 or 40049053 CoolLED DAPI
pE-300white SBFluorescenceSingle36539000 AT Dapi49000 ET DapiLED-DAPI-B
pE-300white SBFluorescenceSingle46049001 ET eCFP49013 ET TealLED-CFP-ALED-mTFP-A
pE-300white SBFluorescenceSingle46049002 ET eGFP39002 AT eGFPGFP-4050BGFP-A-Basic
pE-300white SBFluorescenceSingle46049054 CoolLED GFP
pE-300white SBFluorescenceSingleGYR (525-660)49004 ET Cy349005 ET dsRedTxRed-4040CLED-TRITC-A
pE-300white SB, pE-300white MBFluorescenceSingleGYR (525-660)49055 CoolLED mCherry #149056 CoolLED mCherry #2
pE-300white SBFluorescenceSingleGYR (525-660)49008 ET mCherry39010 AT Tex. RedYFP-2427BLED-mCherry-A
pE-300white SBFluorescenceSingleGYR (525-660)49006 ET CY539007 AT Cy5Cy5-4040C
pE-300white MBFluorescenceSingle40049021 eBFP249028 ET Dapi 395LED-DAPI-B
pE-300white MBFluorescenceSingle46049001 ET eCFP49013 ET TealLED-CFP-ALED-mTFP-A
pE-300white MBFluorescenceSingle46049054 CoolLED GFP
pE-300white MBFluorescenceSingle46049002 ET eGFP39002 AT eGFPGFP-4050BGFP-A-Basic
pE-300white MBFluorescenceSingleGYR (525-660)49004 ET Cy349005 ET dsRedTxRed-4040CLED-TRITC-A
pE-300white MBFluorescenceSingleGYR (525-660)49008 ET mCherry39010 AT Tex. RedYFP-2427BLED-mCherry-A
pE-300white MBFluorescenceSingleGYR (525-660)49006 ET CY539007 AT Cy5Cy5-4040C
pE-300white MBFluorescenceMultiband400, 460, GYR (525-660)69401 – ET Triple Multi LEDLED-DA/FI/TX-A
pE-300white SBFluorescenceMultiband365, 460, GYR (525-660)69401 – ET Triple Multi LEDLED-DA/FI/TX-A
pE-300white SBFluorescenceMultiband460, GYR (525-660)GFP/DsRed-A
pE-300white SBFluorescenceMultiband460, GYR (525-660)59022 ET eGFP/mCherryFITC/TxRed-A
pE-300white MBFluorescenceMultiband400, 46059001v2 ET DAPI/Green FISH
pE-300white MBFluorescenceMultiband400, GYR (525-660)59002v2 ET DAPI/Orange
pE-300white MBFluorescencePinkel400, 460, GYR (525-660)89084v2 ET DAPI/Green/Orange FISHLED-DA/FI/TX-3X-B
pE-300white MBFluorescencePinkel460, GYR (525-660)59222 ET eGFP/mCherryGFP/DsRed-2X-A
pE-300white MBFluorescenceMultiband400, GYR (525-660)59003 v2 ET DAPI/Red FISH
pE-300white SBFluorescencePinkel365, 460, GYR (525-660)LED-DA/FI/TX-3X-B
pE-300white SBFluorescencePinkel460, GYR (525-660)59022 ET eGFP/mCherryGFP/DsRed-2X-A
pE-300white MBFluorescenceMultiband460, GYR (525-660)GFP/DsRed-A
pE-300white MBFluorescenceMultiband460, GYR (525-660)59022 ET eGFP/mCherryFITC/TxRed-A
pE-300-W-D-SB-YYY-ZZ: pE-300white direct fit Light Source, exchangeable microscope adaptor to customer-specified microscope, remote manual control pod, and power supply. Single band filter set configuration
pE-300-W-D-MB-YYY-ZZ: pE-300white direct fit Light Source, exchangeable microscope adaptor to customer-specified microscope, remote manual control pod, and power supply. Multi band filter set configuration
pE-300-W-L-SB-ZZ: pE-300white Light Source for use with 3 mm Liquid Light Guide.  Single Band filter configuration.  Includes light source, stand, control pod & power supply
pE-300-W-L-MB-ZZ: pE-300white Light Source – Multi-Band.  For use with 3 mm Liquid Light Guide.  Multi band filter configuration.  Includes light source, stand, control pod & power supply
pE-1906 1.5 m long, 3 mm diameter liquid light guide
pE-10400-YYY pE-Universal collimator for use with a single liquid light guide.  Includes customer-specified adaptor

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

More information is available on the Accessories tab.

USB-TTL Conversion kit

USB-TTL Conversion kit

pE-Universal Collimator

pE-Universal Collimator

Liquid Light Guide

Liquid Light Guide



The CoolLED pE Driver is first required for software integration, and can be downloaded here.

CompanySoftwareSummaryQuick Start GuideVideo
AndorAndor iQ 
Intelligent Imaging Innovations (3i)SlideBook 
Miltenyi (formerly LaVision) BioTecImSpector Pro  
LeicaLAS X
Media CyberneticsImage-Pro
Molecular DevicesMetaMorph
NikonNIS Elements
Quorum TechnologiesVolocity
Visitron SystemsVisiView  

Contact CoolLED for further information.

The award winning pE-300 Series is a range of LED Illumination Systems for Fluorescence, Optogenetics, Electrophysiology and high speed microscopy applications. It comprises 3 systems providing a solution that covers a range of everyday fluorescence microscopy; from the simple pE-300lite through the classic pE-300white to the highly controllable pE-300ultra.

The table below is a quick reference guide to the features offered by the pE-300 Series systems.

Features pE-300lite pE-300white pE-300ultra
Broad spectrum
Simple to fit and use
Instant on/off
No bulb replacement
Direct or Light Guide delivery options
Long lifetime
Stable & Repeatable - 10-100% intensity control
Filter set compatibility
Mercury free
Individual channel intensity control
Individual channel selection
Integration with imaging software
Global remote triggering (TTL, microsecond)
Individual channel triggering (TTL, microsecond)
Removable inline filter holders
Sequence Runner