Fluorescence is the emission of light by a molecule when it absorbs energy from an external source, such as a light source or chemical reaction. In biological molecules, this phenomenon occurs when certain molecules, such as proteins or nucleic acids, absorb light and re-emit it at a longer wavelength, resulting in a visible glow.
Fluorescence is widely used in biological research as a tool for studying the structure, function, and interactions of molecules. It allows scientists to track the movement and localization of molecules within cells, detect changes in their conformation, and measure their interactions with other molecules.
The fluorescence of biological molecules can be affected by several factors, including the chemical structure of the molecule, its environment, and the presence of other molecules or ions that can interact with it. Additionally, the excitation and emission wavelengths, as well as the intensity and duration of the excitation source, can also impact fluorescence.
Fluorescence can be measured using a variety of techniques, such as fluorescence spectroscopy, fluorescence microscopy, and flow cytometry. These methods involve illuminating the sample with a specific wavelength of light and measuring the intensity and wavelength of the emitted light to determine the fluorescence properties of the molecules.
Fluorescence has numerous applications in biological systems, including imaging and visualization of cellular structures and processes, monitoring of enzyme activity, and detection of biomarkers for diseases. It is also used in drug discovery and development, as well as in medical diagnostics, such as DNA sequencing and protein analysis.