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ApplicationFluorescence Spectrocopy: An Introduction
Antibodies are very sensitive to changes in cells or cell assemblies. Basic idea of the fluorescence spectroscopy is to attach a fluorescence dye to antibodies for using their selectivity for diagnosis and detection purposes.
Fluorescence dyes are pumped optically with a mercury lamp. Due to the relaxation of the excited electrons, the dye emitts fluorecence light with only a minor delay after the optical excitation. The fluorecence light shows a typical red shift of 10nm .. 100nm. This red shift allows to distinguish in between pump light and fluorescence emission.
For applying this method, an assembly of cells is contacted with fluorescence dye attached antibodies. The interaction of the antibodies with cell assembly can be detected optically with the help of fluorescence emission.
Different antibodies can be labeled with different fluorescence dyes. The reaction of each antibody with the cell assembly can be detected individually by the different emission wavlength of the dyes.
Diode Laser Fluorescence Spectrocopy
For more efficient detection, the different decay times of different types of dyes can be used for labeling more antibodies at one time. This method is well known by the name of time resolved fluorescence spectroscopy.
Currently most fluorescence dyes are developed for Ar-Ion and doubled Nd:YAG lasers. Such laser systems are bulky and expencive. Our goal is to enable biomedical researchers to benefit of the progress in the field of diode lasers. Diode lasers are reliable and unexpensive light sources. Major difference between diode lasers and Ar-Ion, doubled Nd:YAG lasers is the emission wavelength. Whereas conventional laser systems operate in the visible spectral range, diode lasers operate in the near infra-red (NIR) spectral regime. NIR is not visible to the human eye. However, it can be easily detected by conventional camera systems.
Diode Laser matching Fluorescence Dyes
Since most fluorescence dyes are devloped for Ar-Ion and doubled Nd:YAG lasers, we started a close cooperation with Squarix GmbH who are specialists for developing special fluorescance dyes. First NIR fluorescence dyes, best matching for diode lasers will be available soon.