ABSTRACT
Multiple wavelength operation in a flow cytometer is an exciting way for cell analysis based on both fluorescence and optical scattering processing. For example, this multiparametric technique is currently used to differentiate blood cells subpopulations. The choice of excitation wavelengths matching fluorochrome spectra (it is currently the opposite) and the use of a broader range of fluorochromes can be made by taking advantage of a filtered supercontinuum white light source. In this study, we first wished to validate the use of a specific triggered supercontinuum laser in a flow cytometer based on white light scattering and electric sizing on human blood cells. Subsequently, to show the various advantages of this attractive system, using scattering effect, electrical detections, and fluorescence analysis, we realized cells sorting based on DNA/RNA stained by thiazole orange. Discrimination of white blood cells is efficiently demonstrated by using a triggered supercontinuum-based flow cytometer operating in a "one cell-one shot" configuration. The discriminated leukocyte populations are monocytes, lymphocytes, granulocytes, immature granulocytes, and cells having a high RNA content (monoblasts, lymphoblasts, and plasma cells). To the best of our knowledge, these results constitute the first practical demonstration of flow cytometry based on triggered supercontinuum illumination. This study is the starting point of a series of new experiments fully exploiting the spectral features of such a laser source. For example, the large flexibility in the choice of the excitation wavelength allows to use a larger number of fluorochromes and to excite them more efficiently. Moreover, this work opens up new research directions in the biophotonics field, such as the combination of coherent Raman spectroscopy and flow cytometry techniques.
Subject(s)
Flow Cytometry/methods , Lasers , Benzothiazoles/chemistry , DNA/chemistry , DNA/metabolism , Fluorescent Dyes/chemistry , Humans , Leukocyte Count , Leukocytes, Mononuclear/cytology , Leukocytes, Mononuclear/metabolism , Leukocytes, Mononuclear/physiology , Light , Nucleic Acids , Quinolines/chemistry , RNA/chemistry , RNA/metabolism , Scattering, RadiationABSTRACT
A theoretical study of optimized single mode Er-doped MOFs designed for high efficiency amplification at 1550nm is carried out, deriving benefit from the demonstrated very low decrease of the overlap factor versus wavelength. In spite of this potential advantage, classical single mode MOFs are first shown to be less efficient than usual Er-doped step index fibers (SIF). However, novel single mode large core MOFs (LCMOFs) are designed, providing overlap factors higher than 0.9 at both the pump and the signal wavelengths. To obtain the same gain, the necessary length of LCMOF is reduced by up to 40% compared to that of Er-doped SIF. Such a highly efficient amplifying fiber is attractive for short pulse and soliton amplification.
