Update: Harvard Strategic Procurement has negotiated discounted pricing for Lumencor light engines for Harvard laboratories. This sustainable option for light boxes is currently being utilized at the Nikon Imaging Center at HMS. Learn more about pricing discounts.

The Nikon Imaging Center at Harvard Medical School is the largest light microscopy facility on the Longwood campus and now thanks to a new approach to lighting it’s also positioning itself as the greenest. The Center is transitioning the light source for 12 of its 13 microscopes to more efficient solid-state light engines, replacing older metal halide bulbs that contain mercury.

For Dr. Jennifer Waters, the Center’s director, the transition to the more environmentally-friendly light source was primarily motivated by a desire to improve the quality of research data rather than the energy or cost savings the lab would realize (though those certainly are an added benefit).

Microscopy allows researchers to use microscopes to view samples and objects that cannot be seen with the unaided eye. It is applied by Harvard researchers in the field of cell and systems biology and cutting-edge biomedical research occurring throughout campus by faculty and students.

As Waters explained in a recent interview, the new light engines produced by Lumencor provide several positive benefits for Harvard-based researchers that ultimately result in higher quality images. Because the intensity of the light stream doesn’t degrade over time the new light engines provide a more stable light source for collecting data. This is of particular importance for providing time-lapse imaging where researchers collect images of the same sample as it changes over time. The older metal halide bulbs were much more unstable, with a tendency to flicker over time impacting the intensity of light and therefore making it difficult for researchers’ to compare quality of light in images of samples collected over a period of time. “The real clincher here is that the researchers using our microscopes will be able to collect images that will allow for more precise quantitative analysis,” said Waters.

I hope we will inspire others using microscopy to consider this more efficient fluorescence illumination option not only for the positive sustainability benefit but also because it leads to better data.

In addition, the older metal halide bulbs were much more energy intensive, requiring a power surge to turn on and cool-down phase in between uses that realistically meant the bulbs would stay on for extended periods of time. For example, a common long-term imaging experiment conducted at the Center would require the acquisition of 50 images (at multiple stage positions) every 30 minutes for 48 hours, with a 100ms camera exposure time. While a mercury light source would need to burn the full 48 hours, light engines can be set up to turn on only when the camera is acquiring an image – a total of 8 minutes for the full experiment. 

It is estimated that the newer light engines will last for approximately 10,000 hours versus the 1500 hours lifespan of the older bulbs. Because the solid-state light engines can be turned on and off in an instant they will last much longer, dramatically reducing the Center’s replacement and disposal costs. The previous metal halide bulbs also contained mercury, a harmful and toxic chemical element that needed to be disposed of in coordination with Environmental Health and Safety.

The Center’s team implemented a six-month pilot program to ensure that the quality of light would meet the demands and expectations of researchers. A Life Cycle Analysis conducted by Harvard’s Green Building Services showed that the cost savings that would result from not having to replace the light source as often were far higher than the expected energy savings. In all, the costs for replacement, operation and disposal were cut in half. After collecting information on the new light source and quality of research data, Waters and her team ultimately decided to expand the new light source to the majority of their microscopes. Funding for the project was provided by the Tools and Technology Program at the Harvard Medical School. 

In transitioning to Mercury Free Microscopy, Dr. Waters is showing that her team can effectively reduce their department’s impact on the environment, while also saving money and improving the quality of data provided to researchers. “I hope we will inspire others using microscopy to consider this more efficient fluorescence illumination option not only for the positive sustainability benefit but also because it leads to better data,” said Waters.