The acronym for light microscope. The study of diatoms relies on a compound light microscope in which a beam of light passes through optical lenses to view an image of the specimen. The light microscope provides images of the transparent features of the diatom.
Contributors to the Diatoms of the United States project use research grade light microscopes with the minimum specifications of a 100x, 1.3 numerical aperature (NA) oil immersion objective lens and 1.3 NA condenser lens.
The scanning electron microscope (SEM) is also important in diatom studies.