| 摘要 |
An optical configuration for flow cytometers which allows the sample stream, which carries the cells to be measured, to be excited in two separate foci of different wavelengths. The excitation light is focussed on the sample stream by a lens (5) which has its optical axis (14) and object plane (7) coinciding with that of another lens (16) situated opposite to it and which is collecting fluorescence and light scattering from said cells and forms fluorescence images of said sample stream in different image planes (19, 20 and 34) which are separated by dichroic mirrors (18, 33). Said lens (16) contains a field stop (17) which stops direct excitation, so that only fluorescence and scattered light reach said image planes (19, 20, 34). Behind said image plane (19), which contains scattered light from said cells, is a telescope (21) which makes an image of said field stop (17) in a plane (23). In said plane (23) are two concentric mirrors (24, 25) which isolate light of small and large scattering angle, respectively, and direct this light onto separate light detectors (30, 32). By means of dichroic mirrors and band filters different spectral components of the fluorescence are separated and directed onto separate light detectors (44, 45, 46, 47). Slits (35, 36, 37) in the image planes (19, 20, 34) eliminate background light from the part of said object plane (7) which does not contain said sample flow. |
