Spectroscopic Properties - Fluorescence Spectrum -
Most proteins exhibit intrinsic fluorescence in the ultraviolet region. This occurs due to the presence of aromatic amino acids such as phenylalanine, tyrosine, and tryptophan amongst the constituent amino acids of the protein. Of the aromatic amino acids, tryptophan fluoresces most strongly. As the fluorescence of a protein’s sensitivity reflects the changes in the microenvironment (differences in pH, polarity, etc.) where the aromatic amino acids exist, fluorescence can be used to analyze the spatial structure of antibodies, in addition to impurity detection.
Compared to absorbance methods, fluorescence sensitivity is tens to thousands times better - this means that you can analyze nanogram to picogram samples with great results. Fluorescence can be used also to identify a specific molecule in a complex background. When the compound of interest does not exhibit natural fluorescence, functional group-specific probes may be used to label the compound and assist your research. The synchronous scanning mode allows mixtures of fluorochromes to be analyzed.