Abstract: An optical component for illuminating a sample region with a periodic light pattern comprises: a first waveguide, a further waveguide and an optical splitter. The optical splitter has an input for receiving light, a first output and a second output. The first waveguide is optically coupled to the first output, to direct the first input light into the sample region in a first direction. The second output is optically coupled to the sample region to direct second input light into the sample region in a second direction. The further waveguide is arranged to receive third input light which is directed into the sample region in a third direction. The first direction, second direction and third direction are different from one another. The first and second input light interferes to form a periodic pattern in the sample region. The optical component may be used for structured illumination microscopy.

Abstract: An optical component for illuminating a sample region with a periodic light pattern comprises: a first waveguide, a further waveguide and an optical splitter. The optical splitter has an input for receiving light, a first output and a second output. The first waveguide is optically coupled to the first output, to direct the first input light into the sample region in a first direction. The second output is optically coupled to the sample region to direct second input light into the sample region in a second direction. The further waveguide is arranged to receive third input light which is directed into the sample region in a third direction. The first direction, second direction and third direction are different from one another. The first and second input light interferes to form a periodic pattern in the sample region. The optical component may be used for structured illumination microscopy.

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: 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: A surface-enhanced Raman scattering method and apparatus to sequence polymeric biomolecules such as DNA, RNA, or proteins is introduced. The method uses metallic nanostructures such as, for example, spherical or cylindrical Au or Ag nanoparticles having characteristic lengths of 10-100 nm which when illuminated with light of the appropriate wavelength produce resonant oscillations of the conduction electrons (plasmon resonance). Electric field enhancements of 30-1000 near the particle surface resulting from such oscillations increase Raman scattering cross-sections by about 106-1015 due to the E4 dependence of the Raman scattering, wherein the largest enhancements occur in the gap/junction between novel closely spaced structures as disclosed herein.

Abstract: Surface-Enhanced Raman Spectroscopy (SERS) is a vibrational spectroscopic technique that utilizes metal surfaces to provide enhanced signals of several orders of magnitude. When molecules of interest are attached to designed metal nanoparticles, a SERS signal is attainable with single molecule detection limits. This provides an ultrasensitive means of detecting the presence of molecules. By using selective chemistries, metal nanoparticles can be functionalized to provide a unique signal upon analyte binding. Moreover, by using measurement techniques, such as, ratiometric received SERS spectra, such metal nanoparticles can be used to monitor dynamic processes in addition to static binding events. Accordingly, such nanoparticles can be used as nanosensors for a wide range of chemicals in fluid, gaseous and solid form, environmental sensors for pH, ion concentration, temperature, etc., and biological sensors for proteins, DNA, RNA, etc.

Abstract: A method and apparatus with the sensitivity to detect and identify single target molecules through the localization of dual, fluorescently labeled probe molecules. This can be accomplished through specific attachment of the taget to a surface or in a two-dimensional (2D) flowing fluid sheet having approximate dimensions of 0.5 ?m×100 ?m×100 ?m. A device using these methods would have 103–104 greater throughput than previous one-dimensional (1D) micro-stream devices having 1 ?m3 interrogation volumes and would for the first time allow immuno- and DNA assays at ultra-low (femtomolar) concentrations to be performed in short time periods (˜10 minutes). The use of novel labels (such as metal or semiconductor nanoparticles) may be incorporated to further extend the sensitivity possibly into the attomolar range.