Optical microscopes use visible light and lenses
(e.g., 10x, 20x, 40x, 100x)
to magnify objects that are not visible to the naked eye.
Fluorescence occurs when matter absorbs light and then emits
light at longer wavelengths.
Microscopes that optically separate
these colors are used to identify phytoplankton.
Scanning Electron Microscopes use electron beams with
wavelengths thousands of times
shorter than visible light,
providing much greater magnification.