Final answer:
Specimens that emit light immediately when viewed under a microscope are described as fluorescent. Fluorescence is the process where substances absorb energy and quickly emit light at different wavelengths, which is utilized in fluorescence microscopy to visualize and contrast biological specimens.
Step-by-step explanation:
When you place a specimen under the microscope and parts of the specimen emit light immediately, these materials can be described as fluorescent. Fluorescence is a process where certain dyes or substances absorb energy, typically from ultraviolet or blue light, and then almost instantly release that energy in the form of photons, emitting light at a different wavelength. The immediate emission of light differentiates fluorescence from phosphorescence, where the emission is delayed.
A fluorescence microscope utilizes fluorescent chromophores called fluorochromes to visualize specimens. These fluorochromes, like Texas red or FITC, absorb energy from a light source and emit this energy as visible light to create contrast. This is instrumental in identifying structures within cells, such as nuclei with DAPI, which stains nucleic acids and emits blue light under ultraviolet illumination.
Different materials have different fluorescent properties based on their atomic energy levels. When you observe immediate light emission under a microscope, it is a clear indication of the fluorescent characteristics of the specimen. This phenomenon is essential for various research and diagnostic applications in biological sciences.