Abstract: Raman spectra of cells, such as normal human T- and B-cells from peripheral blood or human tonsil and the corresponding transformed cells are obtained by optically trapping the cells and obtaining their Raman spectra. The trapped cells can be subjected to one, two, or more different excitation wavelengths, and each wavelength of the corresponding Raman spectra can be stored in a separate channel. In preferred embodiments, two spectra are subtracted from each other to give a difference spectrum and each channel is analyzed independently to characterize the trapped cell. Alternatively, the Raman spectrum can be subjected to Principal Component Analysis (PCA) in order to characterize the trapped cell. The trapped cell thus classified can be sorted, or further manipulated.

Abstract: Methods and systems for reconstructing individual spectra acquired from laser interrogation spots in a 2D array illuminating a particle are described. A particle is positioned in a 2D array that includes multiple laser interrogation spots. The laser interrogation spots of the particle are detected in the 2D array using a spectrometer. Multifocal spectral patterns are generated based on the laser interrogation spots, and an individual spectrum for each laser interrogation spot is reconstructed based on the plurality of multifocal spectral patterns.

Abstract: Methods are disclosed for isolation of a stem-cell derived differentiated cell, which method entails illuminating an incident light onto a plurality of stem-cell derived cells that comprise at least an undifferentiated cell and a differentiated cell possessing a noncentrosymmetric structure, wherein the differentiated cell generates second-harmonic light from the incident light; and isolating the differentiated cell identified by the second-harmonic light. Devices for carrying out the methods are also provided.

Abstract: Methods are disclosed for isolation of a stem-cell derived differentiated cell, which method entails illuminating an incident light onto a plurality of stem-cell derived cells that comprise at least an undifferentiated cell and a differentiated cell possessing a noncentrosymmetric structure, wherein the differentiated cell generates second-harmonic light from the incident light; and isolating the differentiated cell identified by the second-harmonic light. Devices for carrying out the methods are also provided.

Abstract: Methods and systems for reconstructing individual spectra acquired from laser interrogation spots in a 2D array illuminating a particle are described. A particle is positioned in a 2D array that includes multiple laser interrogation spots. The laser interrogation spots of the particle are detected in the 2D array using a spectrometer. Multifocal spectral patterns are generated based on the laser interrogation spots, and an individual spectrum for each laser interrogation spot is reconstructed based on the plurality of multifocal spectral patterns.

Abstract: Methods are disclosed for isolation of a stem-cell derived differentiated cell, which method entails illuminating an incident light onto a plurality of stem-cell derived cells that comprise at least an undifferentiated cell and a differentiated cell possessing a noncentrosymmetric structure, wherein the differentiated cell generates second-harmonic light from the incident light; and isolating the differentiated cell identified by the second-harmonic light. Devices for carrying out the methods are also provided.

Abstract: A double-pass fiber-optic based spectroscopic gas sensor delivers Raman excitation light and infrared light to a hollow structure, such as a hollow fiber waveguide, that contains a gas sample of interest. A retro-reflector is placed at the end of this hollow structure to send the light back through the waveguide where the light is detected at the same end as the light source. This double pass retro reflector design increases the interaction path length of the light and the gas sample, and also reduces the form factor of the hollow structure.

Abstract: A double-pass fiber-optic based spectroscopic gas sensor delivers Raman excitation light and infrared light to a hollow structure, such as a hollow fiber waveguide, that contains a gas sample of interest. A retro-reflector is placed at the end of this hollow structure to send the light back through the waveguide where the light is detected at the same end as the light source. This double pass retro reflector design increases the interaction path length of the light and the gas sample, and also reduces the form factor of the hollow structure.

Abstract: Raman spectra of cells, such as normal human T- and B-cells from peripheral blood or human tonsil and the corresponding transformed cells are obtained by optically trapping the cells and obtaining their Raman spectra. The trapped cells can be subjected to one, two, or more different excitation wavelengths, and each wavelength of the corresponding Raman spectra can be stored in a separate channel. In preferred embodiments, two spectra are subtracted from each other to give a difference spectrum and each channel is analyzed independently to characterize the trapped cell. Alternatively, the Raman spectrum can be subjected to Principal Component Analysis (PCA) in order to characterize the trapped cell. The trapped cell thus classified can be sorted, or further manipulated.