Chameleon Lasers

Arnd Krueger and Ian Read

Cell biologists have long used wavelength discrimination to optically map structure and function at the cellular and subcellular level. The advent of the confocal laser scanning microscope has enabled such observations in three dimensions, close to the diffraction limit. However, the photobleaching and photodamage related to ultraviolet or visible lasers have limited their ability to produce high-quality data from live-cell samples.

Multiphoton techniques have overcome this limitation.¹ Besides minimizing photodamage, multiphoton confocal laser scanning microscopy produces images with a higher signal-to-noise ratio and better spatial resolution than single-photon techniques…