In biological and medical research, fluorescein-biotin (FITC-biotin) is a commonly used tracer for labeling and tracking biomolecules.
Fluorescein is a dye that absorbs specific wavelengths of light and emits fluorescence, which makes the labeled molecule visible under a fluorescence microscope. Biotin, on the other hand, is a naturally occurring B vitamin with a strong affinity and binding capacity. When fluorescein is combined with biotin to form FITC-Biotin, this complex retains both the fluorescent properties of fluorescein and the affinity and binding capacity of biotin.
During tracing, FITC-Biotin binds to target molecules such as proteins, nucleic acids, or cell surface receptors through its biotin-binding capacity. This binding is usually highly specific and relies on the interaction between the biotin and the binding site of the target molecule. This binding not only allows the target molecules to be labeled, but also makes these labeled target molecules visible under fluorescence microscopy due to the fluorescent properties of fluorescein.
In addition to fluorescence microscopy, FITC-BioTin can also be used in combination with other techniques such as immunoprecipitation, western blot, and mass spectrometry. Through these techniques, researchers can gain a better understanding of the properties, functions, and interactions of the target molecules.
However, there are a few things to keep in mind when using FITC-Biotin for tracing. First, fluorescent dyes can be toxic to certain cell types. Second, the photostability of fluorochromes may affect the reproducibility and reliability of experiments. In addition, due to the size and chemistry of the fluorochrome, the functional and kinetic properties of the target molecule may be affected. Therefore, when using FITC-Biotin for tracing, adequate experimental validation and quality control are required.