Combined coherent raman microscope

Description

A combined confocal and multiphoton laser scanning microscope capable of generating confocal fluorescence and coherent Raman images on biological samples. Lot 1: A combined confocal and multiphoton laser scanning microscope capable of generating confocal fluorescence and coherent Raman images on biological samples. The confocal microscope platform should have at minimum four laser lines covering the four widely used fluorescence colours (Blue, Green, Red and Far Red) e.g. 405, 488, 561 and 647 or equivalent with at least 3 high sensitivity descanned detectors e.g. Hybrid or GaAsP PMTs and means of separating fluorescence using a combination of either fixed or spectral filters. The system will ideally be capable of imaging in Fluorescence Lifetime. The microscope should be equipped with a pulsed laser source (>40MHz repetition rate) capable of providing two spatially and temporally overlapped beams with at least one of them tuneable so the frequency difference covers a wide range of typical biological Raman spectra (at least 750-3000 cm-1). The spectral width of the beams should allow for imaging with at least a 12 cm-1 spectral resolution and tuning of the beam should be able to cover a random step in under 2 seconds. The platform should be capable of interrogating Raman bands by Stimulated Raman Scattering (SRS) in the forward detection geometry and Coherent anti-Stokes Raman Scattering (CARS) images in an epi-detected geometry. It should also be capable of acquiring Second Harmonic Generation (SHG) images as well as Two-Photon Excited Fluorescence (TPEF) Images. For SRS images the signal should be obtained with a photodiode using a Lock-in Amplifier to demodulate the signal from a high speed modulated laser (>10MHz) and optimised depending on the speed of scanning. Epi-scattered emissions should be separated from the generating laser light by means of filters and/or spectral filtering techniques onto at least two non-descanned high sensitivity detectors. Further separation of TPEF photons from those generated by SHG or CARS processes using lifetime information from the detector is required.. This was a calloff under APUC framework LAB1028AP under which the Authority is a member utilising the ranked procedure in that framework