An Analysis of Signal Intensity Affected by The Light Spot With Laser Induced Fluorescence Detection

The experiment of capillary electrophoresis (CE) is put up with the laser induced fluorescence detection (LIFD) system made by ourselves. The model same as the actual system is set up in the software of optical simulation. In order to heighten the fluorescence signals intensity, increase the light spot which illuminate in the detection window of capillary instead of the traditional way: make the light spot smallest to obtain the strongest power density. In simulation, change the size of the light spot illuminate in the detection window of capillary; observe the fluorescence signal of PMT (photomultiplier tube) received. The result of the simulation state: increase the size of light spot in the capillary the fluorescence signal of PMT received is improved. The standard sample pGEM-3Zf(+)/Hae III markers is experimented by CE; the result of experiment is corresponding with the simulation.