Fluorophores, also known as fluorescent dyes or fluorescent probes, are molecules capable of absorbing light at specific wavelengths and then emitting light at longer wavelengths. Fluorophores are versatile tools with widespread applications in biomedical research, diagnostics, environmental monitoring, and materials science. They are frequently covalently linked to macromolecules, functioning as markers, dyes, tags, or reporters for molecules such as antibodies, peptides, or nucleic acids. Fluorophores are extensively employed in analytical methods, including fluorescent imaging and spectroscopy, for staining tissues, cells, or materials.
Historically, fluorescein and its amine-reactive derivative, fluorescein isothiocyanate (FITC), have been widely utilized, initially in antibody labeling and later expanding to nucleic acids with carboxyfluorescein. Other commonly used fluorophores include derivatives of rhodamine (e.g., TRITC), coumarin, and cyanine. However, newer generations of fluorophores, often offer enhanced performance characteristics such as increased photostability, brightness, or reduced pH sensitivity compared to traditional dyes with similar excitation and emission properties.
