Using LEDs to Enhance Image Quality and Cell Viability

Since their debut over a decade ago, LEDs have had an ever increasing impact on the world of fluorescence microscopy. To appreciate this growth in popularity, Alex Gramann addresses many of the benefits LEDs have over other traditional light sources and how their use ultimately impacts and improves the quality of the image.

The quality of the sample image, whether projected on the retina of the human eye or on a camera chip, is based on a wide range of optical parameters — including but not limited to the irradiance at the sample plane, the homogeneity within the field of view, and optical aberrations and artefacts — all of which rely on the light source used to illuminate the sample. The light source or microscope configuration will also have an impact on the quality of the image. Concepts such as Köhler illumination and LED filter matching are crucial for capturing the best image. Moreover, the viability of the scientist's sample can be impacted by photobleaching and phototoxicity, further emphasizing the need for understanding the light source's impact on the sample and thus the image.