Final answer:
In fluorescence microscopy, specimens absorb UV light and remit visible light at a longer wavelength, creating high-contrast images.
Step-by-step explanation:
In fluorescence microscopy, a specimen is typically exposed to short wavelength, high-energy light such as ultraviolet (UV) light, which is absorbed by fluorescent chemicals within the specimen. The absorbed light, known as the excitation wavelength, is of shorter wavelength and higher energy. When the fluorescent molecules within the specimen absorb this energy, they become excited and subsequently emit light at a longer wavelength, known as the emission wavelength, which is of lower energy.
This emitted light is usually in the visible spectrum, providing a bright image against a dark background due to selective filtration that blocks the original excitation light from reaching the detection system. In fluorescence microscopy, specimens absorb short-wavelength, high-energy light (usually UV) and remit longer-wavelength, lower-energy visible light. This contrast provides the vibrant images characteristic of this technique.
Fluorescence microscopy relies on excitation wavelengths in the UV range, while the emission wavelengths are in the visible spectrum, resulting in a noticeable shift towards longer wavelengths.