Confocal microscope, multiphoton

Principles: Pulsed, ultrafast infrared lasers excite fluorescent dyes at the focus only - the only place where photon density is high enough to produce fluorescence. With low absorption and next to no scattering loss, the red excitation light penetrates much deeper into tissue. With some tissues it excites fluorochromes at depths of 1 mm. Thanks to the small excitation volume, images of subcellular resolution are obtained. It is only at the focus where the dyes are excited and where the dye can bleach - ensuring unmatched preservation of your fluorescence-labeled specimen.