Final answer:
Synthetic fluorophores, such as DAPI and FITC, target specific biological structures by binding to them directly or through antibodies. They are used in fluorescence microscopy to visualize cellular components by emitting light when excited by UV light. Techniques such as immunofluorescence and FISH employ these dyes for specific targeting within cells.
Step-by-step explanation:
Synthetic fluorophores are chemicals that can absorb light at one wavelength and emit it at another, allowing them to function as fluorescent labels for biological molecules. For example, DNA dyes like 4',6-diamidino-2-phenylindole (DAPI) bind specifically to the DNA due to their affinity for the minor grooves and the overall negative charge of the DNA backbone, allowing them to only stain DNA. Another label, fluorescein isothiocyanate (FITC), can be covalently attached to antibodies that target specific proteins such as microtubules. Once the FITC-labeled antibodies bind to their target, they can be visualized using fluorescence microscopy, where the target structure emits a distinctive green fluorescence.
Fluorescence microscopy, using these fluorochromes, relies on the property that certain substances can emit light when excited by a specific wavelength. This process usually involves the use of UV light for excitation and the visible emission of light to pinpoint the location of the molecule or structure within the cell. Immunofluorescence and fluorescence in situ hybridization (FISH) are two techniques used to target and highlight specific cellular components with these dyes.
CHECK YOUR UNDERSTANDING
Green light has a higher frequency than red light.
Dispersion occurs when white light passes through a prism because the different wavelengths of light are refracted at slightly different angles. Fluorescent dyes emit a different color of light than they absorb due to the Stokes shift, where the emitted light is of a lower energy and hence a longer wavelength than the absorbed light.