This interactive tutorial explores internal optical pathways of the Nikon SMZ1500 stereomicroscope equipped with an epi-illumination intermediate tube and lamphouse. The tutorial initializes with an Endow GFP fluorescence filter combination inserted into the light path and the Beam Intensity slider, which controls the intensity of the light passing through the microscope, set to the midpoint. Use the Filter Cube slider to toggle between three filter sets:

Large specimens, such as larvae, nematodes, zebrafish, oocytes, and mature insects can be easily selected and manipulated when they are labeled with GFP and illuminated by fluorescence techniques with a stereomicroscope. The fluorescence illumination reveals which organisms are producing the fluorescent protein and the stereoscopic vision coupled to a large field of view and ample working distance enables observers to conduct experiments with forceps, pipettes, or micromanipulators. Other, more conventional, specimens are also easily observed and recorded using stereomicroscopes with fluorescence illumination.

The illuminator for epi-fluorescence on a stereomicroscope functions in a manner that is similar to those employed on more complex compound microscopes. Typically, the light source is a xenon or mercury arc lamp contained in an external lamphouse that is attached to the microscope via an intermediate tube (or vertical illuminator) positioned between the microscope zoom body and observation tubes. This type of illumination is currently restricted to applications employing common main objective (CMO) stereomicroscopes, because it is not possible using commercially available parts to adapt a Greenough or converging-type stereomicroscope for fluorescence illumination.